Methods and coatings for protecting surfaces from bio-fouling species

ABSTRACT

Methods of protecting a submerged surface from biofouling animal organisms include applying a first biologically active inner polymer layer on a surface, impregnated with at least one first biologically active agent that kills a juvenile stage of a biofouling animal organism. A second biologically active outer polymer layer is applied on the first biologically active inner polymer layer, impregnated with at least one second biologically active agent that inhibits a larval stage of the biofouling animal organism from attaching to the second biologically active outer polymer layer. The second biologically active outer polymer layer includes a friction-reducing additive selected from the group consisting of silicone powder, PTFE powder, molybdenum disulfide powder, graphene nano-platelets, graphene oxide, and fluorinated graphene powder.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to anti-fouling coatings and processes toprevent bio-fouling of mechanisms and surfaces and, more particularly,to multi-layer anti-fouling coatings that include combinations ofbiostatic and biocidal substances that prevent attachment of bio-foulingorganisms and, for any such organisms that penetrate a biostatic layer,that kill such bio-fouling organisms.

Description of the Related Art

Biofouling or biological fouling is the accumulation of microorganisms,plants, fungi, algae, or animals on surfaces. Antifouling is the abilityof materials or coatings to remove or prevent biofouling by the hugenumber of organisms that are capable of colonizing and growing on wettedsurfaces. While the most problematic of these organisms includeshell-forming, invertebrate calcareous (hard calcium and shell forming)animals such as barnacles, mussels, and shipworms (marine wood borers),with photosynthetic algae also being of concern, up to 4000 differentorganisms comprising over 1700 different species that include fungi,bacteria, bryozoans can develop sufficient biomass on involvedstructures to constitute significant biofouling. The proliferativeability of these organisms is remarkable and has reached a recorded highfor barnacles of 343 kg/m2 in the South China Sea. Large masses ofinvasive biological species interfere with the function of every knowndevice, structure, and surface submerged in either marine or freshwater.

Because biofouling can occur almost anywhere that water is a present,biofouling poses risk to a wide variety of objects such as underwaterconstruction, submerged structures, desalination plants, hydroelectricdam and power installations, navigational and instrumented buoys, oceanwave energy converters, and recreational boating and commercialshipping. With respect to boats and vessels moving and being submergedin water, not only are the boat hulls subject to this phenomenon, butalso engines, internal cooling and piping systems, propellers and otherboat appendages such as struts, shafts, lights, and other structures canhave their function compromised and can even be destroyed by heavyinfestations of unwanted organisms. Fish nets, lobster and crab traps,electrical and support cables, and heat exchangers are further examplesof devices that can be compromised with biofouling. The function ofnavigational and instrumented scientific buoys can be hampered becauseof destruction of instrumentation, and in some cases buoys can even sinkfrom excessive weight gain from the attached weight of the invasivebiofouling biomass. Wave energy harvesting generators can freeze up,lose function, be destroyed, and sink from attached biomasses ofinvertebrates.

Biofouling is a serious problem as related to the shipping industry, inparticular the world shipping industry, and produces several seriousissues via barnacle infestations greatly affecting both the economics ofshipping, the performance of vessels being propelled through the waterby various means, and the release of unwanted carbon emissions on thehealth of the planet. For instance, the hull structure and associatedappendages can be damaged through corrosion and sea water seepage intothe metal, even if the metal is a stainless steel alloy normallyresistant to seawater corrosion. Engine structures can be destroyedthrough overheating by non-functional cooling systems, caused by liquidflow blockage by invasive organisms and corrosion damage. Theaccumulation of biofouling on hulls for a heavy infestation can increasedrag and hydrodynamic friction by up to 60%, translating to a speeddecrease of 10% for a given rate of fuel consumption. To compensate forthis drag, up to a 40% increase in this fuel consumption can be needed.

While these problems are also plaguing the leisure boating industry,from mussel infestations in freshwater and from barnacle infestations insaltwater, the barnacle infestations are more responsive for negativeplanet-wide effects. With fuel typically comprising up to half of marinetransport costs, antifouling methods are estimated to be able to savethe worldwide shipping industry around $60 billion per year ifcompletely effective solutions were implemented. Furthermore, barnaclebiofouling has significant impact on global warming and weather changesdue to increased fuel use, and it contributes to adverse environmentaleffects because of increased emissions of carbon dioxide and sulfurdioxide.

Marine fouling is typically described as following four stages ofecosystem development. The chemistry of biofilm formation describes theinitial steps prior to colonization. 1) Within the first minute, the vander Waals interaction causes the submerged surface to be covered with aconditioning film of organic polymers. 2) In the next 24 hours, thislayer allows the process of bacterial adhesion to occur, with bothdiatoms and bacteria (e.g. vibrio alginolyticus, pseudomonasputrefaciens, etc.) attaching, initiating the formation of a biofilm. 3)By the end of the first week, the rich nutrients and ease of attachmentinto the biofilm allow secondary colonizers of spores of macroalgae(e.g. enteromorpha intestinalis, ulothrix) and protozoans (e.g.vorticella, Zoothamnium sp.) to attach themselves. 4) Within 2 to 3weeks, the tertiary colonizers- the macro- foulers- have attached. Theseinclude tunicates, mollusks and sessile Cnidarians, and the organismsinclude barnacles and shipworms in bodies of salt water, and invasivequagga and zebra mussels in fresh water bodies including rivers, lakes,and estuaries, along with Mediterranean mussels in Asia. Once attached,the larval forms of these macro-fouling organisms develop quickly, andin the case of the barnacle larva, cyprids, once they complete theprocess of metamorphosis into the juvenile form, an event that takesonly 6 to 24 hours to complete after attachment, they immediately beginusing their nascent shell formative process to begin burrowing into theattached surface, eventually developing into a destructive biomass thatreaches maturity in one to five years. The process is similar forinvasive mussel species, quagga and zebra mussels, where the twoinvasive species of mussels overrun the entire sea bottoms and shores ofhuge lakes like Lake Mead, Lake Powell, and the Great Lakes in the US.These invasive animals having spread, along with barnacles in sea waterfrom the area of the Caspian Sea, across Europe, to the US, and to therest of the world by their larval forms carried in ship plumbing andballast tanks, as well as adult forms on the hull and other boatstructures.

The destructive mechanisms by which calcium-forming invertebrates taketheir toll on even the toughest coatings and substrates can beillustrated by the actions of barnacles on 316L stainless steel. Thisalloy is totally impervious and not corrosive in freshwater, andvirtually so in salt water as this alloy requires for protection,especially from the chloride ion in salt water, a passivated thinsurface layer of chromium oxide 100 angstroms thick. The layer ismaintained by constant renewal of the oxide from oxygen dissolved in thewater. The mechanism of barnacle destruction of stainless steel can evenreduce this 316L alloy to rust via barnacle induced bio-corrosion,pitting and crevice corrosion.

A barnacle larva settles on the stainless steel surface by penetratingthe biofilm and metamorphoses to a juvenile adult in 6 to 24 hours,followed by repeated molting cycles secreting its adhesive barnaclecement to spread to fill the gap between the base plate of the enlargingbarnacle and the substrate, curing in over a period of a few hours, andrepeating the process with the shell enlarging each time. The cementreacts with the protective chromium oxide layer thereby disrupting it,especially at the exposed grain boundaries of the metal, creatingchannels for corrosive seawater to flow inside the crevice formed by thebarnacle which, in turn, starts attacking the steel metal grains. Severerusting and the formation of pits occur destroying the steel. The cycleis repeated with every enlargement of the juvenile barnacle untiladulthood is reached, and by that time severe damage has been sustainedover an area of the diameter of the barnacle base, multiplied by thegreat number of barnacles, and the stainless steel surface is destroyed.A very similar process occurs with invasive mussels, though thebio-corrosion is less, for instance on stainless steel leisure boatpropellers, because no chloride ion is present.

Many solutions to biofouling have been deployed over the millennia.Copper sheathing were once used, but the rise of iron and steel shipsiding led to an end to this practice because of the galvanic action andcorrosion resulting from the interaction of copper and iron. Copperoxide-based paints have also been used, but had limited lifespan due toleeching into the water and because of the chemical conversion of thecuprous oxide into less toxic salts which accumulated as a crust whichwould inhibit the further biocide action of the copper.

Self-polishing, tin-based biotoxic paints have been used as well, butwere so toxic that they have been banned worldwide. While modernadhesives permit application of copper alloys to steel hulls withoutcreating galvanic corrosion, copper alone is not impervious to diatomand algae fouling. Furthermore, some studies indicate that copper mayalso present an unacceptable environmental impact, as the fact thatcuprous oxide and other copper salts such as copper thiocyanate areconverted into copper oxychloride, which while bio-toxic for biofoulinganimal species, is also highly toxic to desirable aquatic species,leading to it being banned from use in several jurisdictions.

SUMMARY

A method of protecting a surface from biofouling includes applying afirst biologically active inner polymer layer on a surface, impregnatedwith at least one first biologically active agent that kills a juvenilestage of a biofouling animal organism. A second biologically activeouter polymer layer is applied on the first biologically active innerpolymer layer, impregnated with at least one second biologically activeagent that inhibits a larval stage of the biofouling animal organismfrom attaching to the second biologically active outer polymer layer.The second biologically active outer polymer layer includes afriction-reducing additive selected from the group consisting ofsilicone powder, PTFE powder, molybdenum disulfide powder, graphenenano-platelets, graphene oxide, and fluorinated graphene powder.

A method of protecting a surface from biofouling includes applying afirst biologically active inner polymer layer on a surface, the firstbiologically active inner polymer layer comprising at least one firstbiologically active agent that kills a juvenile stage of a biofoulinganimal organism on contact with the first biologically active polymerlayer. A perforated, rigid sheet of fiberglass is placed on a surface ofthe first biologically active inner polymer layer. A second biologicallyactive outer polymer layer is applied on the first biologically activeinner polymer layer and the perforated, rigid sheet of fiberglass. Thesecond biologically active outer polymer layer includes at least onesecond biologically active agent that prevents a larval stage of thebiofouling animal organism from attaching to the second biologicallyactive outer polymer layer. Applying the second biologically activeouter polymer layer causes material of the second biologically activeouter polymer layer to flow through perforations in the perforated,rigid sheet of fiberglass and up against the first biologically activeinner polymer layer, such that an inner surface of the perforated, rigidsheet of fiberglass is immersed in the first biologically active innerpolymer layer and an outer surface of the perforated, rigid sheet offiberglass is immersed in the second biologically active outer polymerlayer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts a cross section of an anti-fouling coating with an outerbiostatic polymer layer and an inner biocidal polymer layer;

FIG. 1B depicts a cross section of an anti-fouling coating with an outerbiostatic polymer layer and an inner biocidal polymer layer with anouter polymer primer between the two polymer layers;

FIG. 1C depicts a cross section of an anti-fouling coating with an outerbiostatic polymer layer and an inner biocidal polymer layer with aninner polymer primer beneath the inner biocidal polymer layer and anouter polymer primer between the biocidal inner polymer layer and thebiostatic outer polymer layer;

FIG. 2A depicts a cut-away view of an anti-fouling coating with an outerbiostatic polymer layer fused together with an inner biocidal polymerlayer;

FIG. 2B depicts a cut-away view of an anti-fouling coating with an outerbiostatic polymer layer fused together with an inner biocidal polymerlayer with a composite fiberglass laminate;

FIG. 2C depicts a cut-away view of an anti-fouling coating with an outerbiostatic polymer layer containing biocides, an outer polymer primercontaining structural additives and biocides, an inner biocidal polymerlayer containing biocides and structural additives, and an inner polymerprimer containing structural additives;

FIG. 3 illustrates graphs of the concentrations of biostatic biocide andbiocidal biocide with depth into the anti-fouling coating with respectto the water surface for 6 different embodiments of coatings;

FIG. 4 illustrates three methods of re-constituting the inner polymerlayer and the outer polymer layer (not shown) and the entireanti-fouling coating;

FIG. 5A depicts a cut-away view of biofouling larval forms beingincompletely prevented from permanently attaching with a singlebiostatic biocide being present in the outer polymer layer;

FIG. 5B depicts a cut-away view of biofouling larval forms beingcompletely prevented from permanently attaching with two biostaticbiocides being present in the outer polymer layer;

FIG. 6A depicts cut-away views showing additional inhibition ofattachment of 3 classes of invasive plant biofouling species with analgaecide added to the outer biostatic polymer coating containing abiostatic biocide in high concentration, and a biocidal biocide in lowconcentration;

FIG. 6B depicts cut-away views showing additional inhibition ofattachment of 3 classes of invasive plant biofouling species with analgaecide added to the outer biostatic polymer coating containing twobiostatic biocides at high concentration;

FIG. 7 depicts the sequential process of biofouling control with first,cyprid larval barnacle attachment or veliger larval mussel attachmentinhibition and then second, death of juvenile barnacle or musselorganism;

FIG. 8 depicts a cut-away view showing two biostatic biocides in theouter biostatic polymer layer (cupro-nickel alloy and low concentrationpyrethrin) and two biocidal biocides in the inner biocidal polymer layer(Lufenuron and high concentration pyrethrin with piperonyl butoxide);

FIG. 9 depicts the erosive damaging bio-corrosion caused by hardcalcareous biofouling organisms including mussels and barnacles;

FIG. 10A depicts 4 cut-away views that illustrate the protectiveshielding effect of the outer biostatic polymer layer on the inner morepotent biocidal polymer layer using various biocidal and biostaticbiocides;

FIG. 10B depicts 6 cut-away views that illustrate several additionalvariation embodiments of the anti-fouling coating;

FIG. 10C depicts a cut-away view of an embodiment of the anti-foulingcoating designed for rapid velocity water craft showing the presence ofan algaecide and multiple low friction filler components;

FIG. 10D depicts a cut-away view of an embodiment of the anti-foulingcoating designed for eradicating heavy encrusted invertebrate biomassesfrom surfaces such as a beach or a lake bed;

FIG. 11A depicts a propeller of a boat or ship coated with ananti-fouling coating comprising the current invention;

FIG. 11B depicts a cut-away view of the propeller's thickness and showncoated with the outer biostatic polymer layer and the inner biocidalpolymer layer also functioning as an inner polymer primer layer withIvermectin as the biocidal biocide and capsaicin as the biostaticbiocide, with the presence of boron carbide particles in the primerlayer;

FIG. 12A depicts a cut-away view of a boat's fiberglass hull thatcontains no biocide but is covered by a biocidal inner polymer layercontaining both a biocidal biocide in high concentration and a biostaticbiocide in low concentration and a “gelcoat” outer biostatic polymerlayer containing both a biostatic biocide in high concentration and abiocidal biocide in low concentration;

FIG. 12B depicts a cut-away view of a boat's fiberglass hull thatcontains no biocide but is covered in the same manner as the hull inFIG. 12A but in addition, an inner polymer primer lies between the hulland the inner biocidal polymer layer;

FIG. 12C depicts a cut-away view of a boat's fiberglass hull thatcontains both a biocidal biocide in high concentration and a biostaticbiocide in low concentration, both added to the fiberglass at the timeof manufacture of the boat, making the hull the inner biocidal polymerlayer which is covered by a “gelcoat” outer biostatic polymer layer of abiostatic biocide in high concentration, a biocidal biocide in lowconcentration, and which also contains an algaecide, a pyrithione metalsalt;

FIG. 13A depicts a diagram of a boat and its transportation accessoryequipment illustrating structures that require anti-fouling protection;

FIG. 13B depicts a diagram of a power station water intake systemdownstream from a dam that requires anti-fouling protection;

FIG. 13C depicts a hybrid off shore wind and wave farm indicatingstructures that require anti-fouling protection;

FIG. 14A depicts cross section and side cut-away views of a pipe withoutimpregnated biocide coated on the inside, the outside, or both with aninner biocidal polymer layer and an outer biostatic polymer layer;

FIG. 14B depicts cross section and side cut-away views of a plasticpolymer pipe with impregnated biocide acting as the inner biocidalpolymer layer and coated on the outside, or inside, or both with theouter biostatic polymer layer;

FIG. 15A depicts a cross section cut-away view of a polymer pylon orcolumn impregnated with biocide serving as the inner biocidal polymerlayer covered on its surface by the outer biostatic polymer layer;

FIG. 15B depicts a cut-away view of a wall comprised of plastic polymerbricks impregnated with biocide serving as the inner biocidal polymerlayer covered on its surface by the outer biostatic polymer layer;

FIG. 15C depicts a cut-away structure comprised of concrete whose innerportions are impregnated with a biocidal biocide impregnated liquidpolymer to form an inner biocidal polymer layer and whose outer surfacesare covered with an outer biostatic polymer layer;

FIG. 16A depicts a spring coated with an inner biocidal polymer layerand an outer biostatic polymer layer;

FIG. 16B depicts a flexible, stretchable bungee cord coated with aninner biocidal polymer layer and an outer biocidal polymer layer;

FIG. 17A depicts a fiber coated with an inner biocidal polymer layer andan outer biostatic polymer layer, a fiber impregnated with a biocide tofunction as an inner biocidal polymer layer, a rope made with such fiberthat would be protected from invertebrate biofouling attachment;

FIG. 17B depicts a lobster trap coated with an antifouling coatingcomprised of an inner biocidal polymer layer and an outer biostaticpolymer layer;

FIG. 17C depicts a fishnet coated with an antifouling coating comprisedof an inner biocidal polymer layer and an outer biostatic layer or ifthe fiber is impregnated with a biocide functioning as an inner biocidalpolymer layer, it is then coated with just an outer biocidal polymerlayer;

FIG. 17D depicts rigid stainless steel cable with various woven cableconfigurations within a polymer jacket including a 1×1 central metalcable, a 1×19 woven central metal cable, a 7×7 woven central metalcable, and a 7×19 woven central metal cable, each surrounded by andimpregnated with an inner biocidal polymer layer that contains biocidesrelevant to this invention incorporated into the polymer at the time ofmanufacture, and this inner biocidal polymer layer in turn is covered byan outer biostatic polymer layer;

FIG. 17E depicts an undersea submarine cable jacketed by multiplestructural layers around the central information-carrying opticalcables, with an outer jacket of polyethylene which can be impregnatedwith an inner biocidal polymer layer and in turn covered by an outerbiocidal layer at the time of manufacture;

FIG. 18A depicts side-view and cross-sectional cut-away of both a honeycomb and a linear sleeve filter whose filter media is coated with anantifouling coating comprised of an inner biocidal polymer layer andouter biostatic polymer layer;

FIG. 18B depicts a side view of a two layer filter having an upper firstlayer of filter media coated with an outer biostatic polymer layercontaining a high concentration of the biostatic biocide capsaicin and alow concentration of the biocidal biocide ivermectin and into whichwater contaminated with biofouling larvae flows and which overlies alower second layer of filter media coated with an inner biocidal polymerlayer containing a high concentration of the biocidal biocide,ivermectin, and a low concentration of the biostatic biocide, capsaicin,and out of which water flows filtered free of biofouling larval forms;

FIG. 18C depicts a side view of the two layer filter depicted in FIG.18B but with the first layer of filter media being coated with an outerbiostatic polymer coating which is also impregnated with an additionalbiocide, a herbicide comprising a pyrithione metal salt that serves asan algaecide, fungicide, and bactericide;

FIG. 19A depicts a side view of a filter with filter polymer mediacomprising either activated charcoal (AC), or graphene nano-platelets(GNP) or both, impregnated with biocides in such a manner so as toproduce an upper outer biostatic polymer layer with a high concentrationof the biostatic biocide, capsaicin, and a low concentration of thebiocidal biocide, ivermectin, into which water contaminated withbiofouling larvae flows, and a lower inner biostatic polymer layer witha high concentration of the biocidal biocide, ivermectin, and a lowconcentration of a biostatic biocide, capsaicin, and out of which waterflows filtered free of biofouling larvae.

FIG. 19B depicts a side view of a filter with the same two polymer layerstructure comprising AC, GNP, or both and containing the biocidescapsaicin and ivermectin, but in addition, a second biocidal biocide,lufenuron, in high concentration in the second lower inner biocidalpolymer layer, and in addition, the algaecide, a metallic salt ofpyrithione, is also added to and impregnating the upper outer biostaticpolymer layer;

FIG. 19C depicts a cut-away view of a two polymer layer structuredfilter in a pipe comprised of AC, GNP, or both and in which the upperouter biostatic polymer layer into which water contaminated withbiofouling larvae flows and which is impregnated with a highconcentration of the biostatic biocide, capsaicin, a low concentrationof the biocidal biocide, ivermectin, and a low biostatic concentrationof the biocide pyrethrin and a lower inner biocidal polymer layer out ofwhich water filtered free of biofouling larvae flows and which isimpregnated with a high concentration of the biocidal biocide,ivermectin, a high concentration of the biocidal biocide, lufenuron, anda low concentration of the biostatic biocide capsaicin.

FIG. 19D depicts a cut-away view of a two polymer layer filtercomprising a filament filter medium whose biocides are selected to beantiviral and which are applied to the filament filter medium comprisingthe filter and which incorporates both a UV LED light source and a highvoltage electrostatic negative ion electric generator all containedwithin the filter canister.

FIG. 19E depicts a cut-away view of a two polymer layered filtercomprising a particle filter medium consisting of AC, GNP, or both andin which whose biocides are selected to be antiviral and which areadsorbed onto the particles of the filter medium and which incorporatesboth a UV LED light source and a high voltage electrostatic negative ionelectric generator all contained within the filter canister.

FIG. 20A depicts a schematic and cut-away view of a wave energyconverter coupled to a floating sea water electrolysis unit viaelectrical cables and a water intake filter having a first outerbiostatic layer of filter media coated with a polymer impregnated with abiostatic biocide and a second inner biocidal layer of filter mediacoated with a polymer impregnated with a biocidal biocide;

FIG. 20B depicts a schematic diagram of a raw water engine coolingsystem protected from internal biofouling by a water intake filterhaving a first outer biostatic layer of filter media coated with apolymer impregnated with a biostatic biocide and a second inner biocidallayer of filter media coated with a polymer impregnated with a biocidalbiocide;

FIG. 21A gives a table of low water solubility insecticides effectiveagainst invasive invertebrate biofouling organisms;

FIG. 21B gives a table of low water solubility miticides effectiveagainst invasive invertebrate biofouling organisms;

FIG. 21C gives a table of low water solubility herbicides effectiveagainst invasive plant biofouling organisms; and

FIG. 21D gives a table of natural plant alkaloids that are known to benatural pesticides of organisms belonging to the phylum Arthropoda.

DETAILED DESCRIPTION

Embodiments of the present invention place environmentally safeantifouling formulations, specifically optimized for any givenappropriate application, onto any stationary or moving structure ormaterial surface in contact with or submerged within either marine orfresh bodies of water. The present embodiments prevent and controlbiofouling of structural surfaces submerged in still or moving saltwateror freshwater by invasive, invertebrate, calcium-forming biofoulingspecies such as mussels, barnacles, and shipworms. These embodiments mayinclude a multi-layer polymer coating structure of variable thicknesspolymer layers impregnated with biocides whose composition within thecoating varies with depth from the surface of the water. The compositionof biocides impregnating an outer portion of the antifouling coatingproduce a primarily biostatic antifouling effect, preventing andinhibiting all larval forms of invertebrate organisms from attaching andinhibiting their permanent implantation on the protected surface, andthe composition of biocides impregnating an inner portion of theantifouling coating produce a primarily biocidal effect by killing oncontact all invasive organisms that have metamorphosed to the juvenileform and that have managed to penetrate the outer biostatic polymerlayer secondary to partial resistance to the biocides in that layer. Theouter biostatic polymer layer acts to shield the inner biocidal polymerlayer, which has the more potent biocidal biocides, from contact withthe water, reducing any chance for undesirable effects on the aquaticenvironment and its beneficial lifeforms. Complex differingmulti-biocide compositions within the two polymer layers are chosen toemploy poly-chemotherapeutic principles of human cancer chemotherapy andhuman infection antibiotic therapy, producing more effective attachmentinhibition, lethality, cessation of reproduction, less chance ofdeveloping resistant biofouling strains, and finally stopping theproliferation and spread of these organisms.

Because attachment of algae encourages biofouling organism implantationand is of cosmetic concern to the leisure boating industry, a phytotoxicalgaecide may also be impregnated into the outer polymer layer. Whilethe present embodiments prevent and eradicate hard biofoulinginvertebrate agents, with a modification of adding one additionalbiocide, an algaecide such as pyrithione salt mixture that is alsorelatively insoluble in water and thus again will not releaseundesirable heavy metal ions into the surrounding water, someembodiments can be biocidal to algae, bacteria, and fungi, and biofilm.Buildup of biofilm is the precursor for the invasion of soft algaebiofouling organisms and its associated unpleasant cosmetic effects, andis also the precursor for the invasion of hard invertebrate biofoulingorganisms and their associated destructive effects.

The present embodiments provide biocidal coatings that are safe to theaquatic environment and the benign and beneficial organisms that reside,that cause minimal effect on both the animal and human food chains, thatare safe with respect to human exposure and human carcinogenicity, andthat are cost effective, economical, and available in commercially largequantities. As a result, many of biocides that are most suitable for thepurposes of the present embodiments are naturally derived plantcompounds, and the few artificially constructed molecules as well asmetal derived biocides are chosen to not only provide anti-foulingfunction but also to be completely safe for the aquatic environment andthe benign and beneficial organisms that reside in that environment.

Defining Basic Terms:

Biofouling organisms: Organisms which have the ability to attach to,colonize on, proliferate on, and then penetrate the surface of objectsor the protective surface of such objects that are exposed to orsubmerged in aquatic environments including salt water, fresh water, andbrackish water, resulting in the cosmetic defacement, corrosion,decomposition, and destruction of such surfaces, and if the surfacesinvolve structures moving within the aquatic medium, interference withsuch motion through increase frictional resistance; “Soft” biofoulingorganisms include: bacteria, mold and fungi, freshwater and marinegreen, blue green algae, gold algae (diatoms), and marine and freshwaterseaweeds; “Hard” biofouling organisms include calcareous calcium,chitin, and shell Forming Organisms that include (but are not limitedto) the following classes of biofoulers:

Barnacles—Kingdom: Animalia, Phylum: Arthropoda, Subphylum: Crustacea,Class:

Maxillopoda, Subclass: Cirripedia, Family: Theoctraca, Genus: Balanus,Species: B. Grandula (common acorn barnacle), B. Crenatus (CrenateBarnacle), B. nubilus (Giant Barnacle), B. perforates, B. Amphibalanusimprovisus (Bay Barnacle), Megabalanus coccopoma (Titan Acorn Barnacle,Georgia), B. Balunus, B. Amphitrite, and Polliceipes polymerus(Gooseneck Barnacles), and approximately 50 others; they are chitin andcalcium forming;

Mussels—Kingdom: Animalia, Phylum: Mollusca, Class: Bivalvia, Order:Veneroida, Family Dreissenidae, Genus: Dreissena; they are calcium andchitin forming organisms that include:

Zebra Mussel—Species: Dreissena polymorpha,

Quagga Mussel—species: Dreissena bugensis

Mediterranean Mussel—Order: Mytiloida Family: Mytilidae Species Mytilusgalloprovincialis (Invasive in Asia only);

Marine Shipworms (Marine Woodborers)—Kingdom: Animalia, Phylum:Mollusca, Class: Bivalvia, Order: Myoida, Family—Teredinidae, Genus:Teredo, T. Navalis (most prevalent), Xylophaga dorsalis, Psiloteredomegotara, Nototeredo norvagica; Crustacea Family—Limnoria lignorum(“gribble”); they are chitin and calcium forming organisms;

Bryozoans—Chitin and calcium forming species—many.

Invasive non-barnacle crabs and shrimps—Kingdom: Animalia, PhylumArthropoda, Subphylum: Crustacea, various Genus and species;Glabrophihummus seminudus (Pilumnid crab—native to central Pacific andinvasive to Hawaii via ships from Guam), Carup tenuipes (portunidcrab—native to the Atlantic and invasive via the Suez Canal to theMediterranean Sea spreading by ships to New Zealand and Hawaii),Gonodactylaceus randalli and Gonodactylaceus falcatus (mantis shrimpsvia US navy ships from their native Phillipines to Hawaii) and others;they are chitin and calcium forming organisms.

Polymer—refers to a member of a class of chemical compounds or mixtureof chemical compounds formed by the process of polymerization where twoor more molecules combine to form larger molecules that containmolecular chains of repeating structural units. The pertinent classes ofpolymers relevant to this invention which can comprise either one or twopart liquid polymers for coatings or solid polymers for comprising threedimensional structures include as representative examples, plastics, andnon-plastic polymers:

Plastics:

Member sub-classes of this class of compounds with representativeexamples include:

Poly vinyl chlorides—Plasticized, un-plasticized, and high impact,chlorinated PVC, and others;

Polystyrenes—High impact, general purpose, ABS(acrylonitrile-butadiene-styrene copolymer),

Styrene-Acrylonitrile copolymer, Styrene-butadiene-styrene co-polymer,Styrene-Butadiene, and others;

Celluloses—Cellulose acetate, cellulose acetate-butyrate, celluloseacetate-propionate, Cellulose Propionate, and others;

Polyethylenes—Low density Polyethylene, Medium Density Polyethylene,very low density Polyethylene, chlorinated polyethylene, polypropylenehomo-polymer and copolymer,

High density polyethylene, ultra-high molecular weight polyethylene, andothers;

Acrylics—Polymethylmethacrylate, Polyphenylene oxide, Polycarbonate,ethylene-vinyl acetate, ethylene-methyl acrylate and others;

Nylons—Polyamides of many types;

Polysulphones—of many types;

Liquid crystal polymers—many types

Fluoropolymers—polytetrafluoroethylene (PTFE), polyfluoroethylenevinylether (PEVE), (also known as fluoroethylenevinyl either (FEVE)),poly-flourourethanes, perfluorosulfonic acid, Perfluoropolyethelyneeither,

and many others;

Resins: acrylic resins, epoxy resins, phenolic resins, polyurethaneresins, polyester resins, and others;

Non-Plastic Polymers:

Silicon Based Polymers—silicones (polysiloxanes), silanes, siliconeRubber—liquid and gel, fluorosilicones, and others;

Rubbers—natural rubber (latex, isoprene, cis poly-isoprene), neoprene(poly-chlorprene),

-   -   BUNA-S (butadiene-styrene co-polymer), BUNA-N (nitrile rubber),        butyl rubber,    -   Ethylene-propylene-diene-monomer (EPDM), acrylic rubber,        fluoroelastomers (Viton),

and others.

Pure Carbon Polymers—graphite, activated carbon, graphene, graphenenano-platelets, graphene oxide, graphene fluoride.

Primer—or undercoat, is a preparatory coating put on materials beforepainting of a coating or topcoat, so as to ensure better adhesion of thepaint or coating to the underlying surface, that in addition increasesdurability of the applied coating or paint, provides for uniformity inthe coating's thickness, prevents bleed through of impurities from thesurface being painted, and provides additional protection, by buildingup the primer thickness with repeated coats, for the material beingpainted. A primer's composition may include varying amounts of resins ofthe categories defined above under resin polymers, solvents, pigments,particulates to reinforce the primer such as Kevlar, silica, fluorspar,carbon fiber, boron and other carbides including silicon and metalcarbides, cubic boron nitride, industrial grade diamond, and stainlesssteel fragments, as well as other chemicals and particulate additives.

Examples of primers include:

Self-Etching Primers including acid and zinc chromate, zinc phosphateprimers; epoxy primers, zinc rich epoxy primers, polyester primers,latex primers, poly-vinyl acetate primers, acrylic primers, and urethaneprimers. The zinc rich-epoxy polymer primer has excellent antifoulingproperties because of the zinc powder component, which may be as high as90% (by weight) of the primer.

For the purposes of the present embodiments, there are four structuralclasses of polymers that compose the structure of the antifoulingcoating. They are designated as follows:

Polymer-O, an outer, biostatic polymer topcoat exposed to the waterenvironment, that covers a second biocidal inner polymer that may alsobe a polymer primer layer;

Polymer-I, an inner, biocidal polymer undercoat that is not exposed tothe water environment and covers either the surface to be protecteditself or covers a primer polymer that covers the surface to beprotected;

Primer-O, an outer polymer primer that, if used, would be used betweenthe outer Polymer-O layer and the inner Polymer-I layer;

Primer-I, an inner polymer primer or non-polymer primer that, if used,would lie between the inner Polymer-I layer and the surface to beprotected.

A pesticide, or biocide is defined as any substance toxic to undesirableplant and animal life and may include any chemical agent (includingmetals, alloys, or inorganic salts of metals or alloys), organicchemical, or metallo-organic chemical capable of preventing unwanted orinvasive biological organisms, including animals (insecticides,herbicides, ascaricides, mitocides) or plants (herbicides, algaecides,fungicides, bactericides), from proliferating either through directkilling of their cells by interference with cellular metabolic processes(a biocidal biocide), or by creating an unfavorable environment so that,while they are not killed, they will not colonize an area andproliferate (a biostatic biocide).

Of particular relevance is the subclass of pesticides that have lowwater solubility, low leachability, low aquatic toxicity, and low humantoxicity. This subclass may be divided into two further subclasses,organic pesticides and the metal-derived pesticides, with a small numberof organo-metallic pesticides that have characteristics of both. Thepertinent classes of pesticides include members of the chemical classesof compounds listed below that possess a low water solubilityrequirement of <100 mg/ml, (100 mcg/microliter) but preferably <20 mg/ml(20 mcg/microliter).

Exemplary insecticides that can be used in the present embodimentsinclude insecticides listed in FIG. 21A; mitocides listed in FIG. 21B;Herbicides listed in FIG. 21C; Natural plant alkaloids such as capsaicinlisted in FIG. 21D as well as other Chinese herbal insecticides inparticular for instance, the extract of Triptergium wilfordii (thundergod vine) which contains three potent insecticides—celastrol,triptolide, and wilforine with favorably extreme water solubilities of<1 mg/L, 0.017 mg/L, and <1 mg/L respectively; Organic hydrocarbonanti-helminthics such as ivermectin but also including a large number ofchemical analogues known as macrocyclic lactones, natural productsoriginally derived from soil fungi and bacterial organisms and theirchemical derivatives, a family of drugs known as the avermectins(Abamectin, Aversectin C, Doramectin, Emamectin, Eprinomectin,Ivermectin, Selamectin, Milbemectin, Mibemycin, Moxidectin, Lepimectin,Neamdectin, Spinosad, and Spinetoram, and others), as well as otheranti-helminthics such as albendazole and its chemical analogs with lowwater solubility (<1 mg/L) as well as lufenuron with an extremely lowwater solubility of <0.06 mg/L; inorganic and metallo-organicpesticides—only Cupronickel (90% Cu, range 66-33%; 10% Ni, range 9-30%;1% Fe, 1% Mn) and its closely related alloys cuprozinc and cuprosilver,are relevant as useful to the present embodiments, as the others—coppermetal, copper oxide, copper thiocyanate, zinc metal, zinc oxide, andmost certainly tributyltin (TBT) are considered too toxic to the aquaticenvironment to be desirable for the present embodiments, even though afeature of the present embodiments allows these metal biocides to besafely used by prevention of chemical leaching into the surroundingwater. Nevertheless, TBT is expected to be permanently banned, and insome jurisdictions, copper salts are also being banned. Further examplesinclude miscellaneous agents such as amitriptyline, imitriptyline andother chemical analogs of the tricyclic human anti-depressantmedications; Pyrethrins and Pyrethrinoids including: Bifenthrin,Cyfluthrins, Cypermethrins, Cyphenothrin, Deltamethrin, d-phenothrin,Esfenvalerate, Etofenprox, Fenpropathrin, Flumethrin, cyhalothrins,Imiprothrin, Momfluorothrin, Prallethrin, Permethrin, Pyrethrins,Fluvalinate, Tefluthrin, Tetramethrin, and others.

The ideal biocide for the purposes of the present embodiments has thefollowing characteristics: 1) a large molecule with a high molecularvolume, allowing it to be better trapped within a polymer moleculematrix; 2) a high adsorption coefficient (KOC) as defined approximatelyas the ratio of the concentration of the biocide in the aqueous solutionabove a matrix to the concentration of that biocide in that matrix whichmay be soil or for the purposes of this invention, a polymer molecularmatrix, where a high KOC indicates a high affinity for the matrix and alow affinity for the solution above the matrix; 3) low water solubility,which is related to factors 1) and 2); 4) low chemical leaching ratewhich is related to factors 1), 2), and 3); 5) Low environmental hazardto benign and beneficial organisms in the aquatic environment which isrelated to factors 1), 2), 3) and 4) as well as the biocide's intrinsictoxicity to such organisms; 5) no chlorine atoms or metal atoms, such astin, incorporated into the biocide's organic molecular structure aschlorinated hydrocarbons and compounds such as TBT are quite toxic toenvironmental animal life relative to other; 6) biocides not havingaffinity for the food chain of higher organisms such as fish and humansleading to toxic effects in those species, including humancarcinogenicity; 7) The ability for the biocide to biologically orspontaneously be degraded in the environment such as by UV light; 8) Lowtoxicity to commercial crustaceans, mollusks, and other beneficialorganisms; 9) Absence of delayed toxicity, including carcinogenic,teratogenic, and mutagenic effects; 10) Wide spectrum of organismactivity; 11) Simultaneous effects on settlement, adhesion, attachment,and causation of significant lethality before extensive growth andmaturation followed by proliferation has occurred; 12) High potencyallowing small loading factor concentration in the polymer matrix andlong effective life; 13) Relatively safe for humans to apply as abiofouling coating; 14) Multi-year protection; and 15) Having a lowdiffusion constant, making the biocide more difficult to leach out intothe water.

In general, a very high KOC is associated with a very low watersolubility. For example, with respect to soil and water runoff,ivermectin has a very high KOC of 12660 to 15700 and a low watersolubility of 4 mg/L; pyrethrins have a very high KOC of >100,000 andwater solubilities as low as <0.1 mg/L, while spinosad D, anothermacrocyclic lactone derived from a fermentation bacteria, has a KOC of34,600 and a water solubility of only 0.5 mg/L. Exceptions do occur, anda high KOC may characterize a compound with a high water solubility,indicating that it dissolves well in water while at the same time beingattached to the matrix underneath—these compounds are not suitable forbiocides for the purpose of the present embodiments as they areconsidered too toxic. However, if the adsorption coefficient is quitehigh, a somewhat higher water solubility of the biocide can be toleratedfor this invention, such as commercial mixtures of 5:1 of spinosad A andD with a water solubility of 89 mg/L and 0.5 mg/L respectively but witha KOC 34,600 would still be useful as a biocide. It is specificallycontemplated that biocides with a water solubility of <20 mg/L, and aKOC of at least 10,000 will be used with the present embodiments, but awater solubility of up to 100 mg/L and a KOC as low as approximately 500may be used instead.

Although chlorination of an organic molecule is generally associatedwith high water solubility, high toxicity to benign and beneficialorganisms in the aquatic environment, and a low KOC, if the molecule hasmany fluoride atoms as well, a high level of fluoridation of themolecule will make it highly water insoluble because of thehydrophobicity of the multiple carbon fluorine bonds, making acceptablefor use with this invention. For instance, lufenuron has 2 chlorineatoms but 8 fluorine atoms, resulting in an exceptionally low watersolubility of <0.06 mg/L.

Low water solubility does not guarantee a lack of aquatic toxicity, asvarious organo-tin compounds such as TBT have water solubilities rangingfrom 1.0 to 20 mg/L but are nevertheless far too toxic for use. TBTtoxicity is not just based on its water solubility but also on the factthat the ablative paint that is impregnated with it disintegrates aswell into the water with time, leaving toxic residues in the oceansediment that persist for decades. Whatever the water solubility of thebiocide is, no matter how low, if the resulting concentration of thebiocide in the aquatic environment is still above the toxic range, as isthe case with TBT, it would generally be too toxic for use in thepresent embodiments. However, even in this case, one particularembodiment of this invention can make even the use of TBT safe for theenvironment.

Water solubility is related to the chemical leaching rate of thebiocide, which not only affects the toxicity of the biocide to desirableaquatic life but also affects the longevity of the effectiveness of thebiocide. It has been shown by the paint industry, with measurements onorgano-tin and copper paints, that the release rate of the biocidesteadily drops for the first 14 days and then stays approximatelyconstant until the end of the useable life of the biocide coating, atwhich point about 30% of the remaining biocide stays within the coatingand is never released and about 70% has been released. Thus, theeffective operational life of the coating is dependent on theconcentration by weight and therefore total amount of biocide in thecoating. How long it takes that 70% to be released depends on therelease rate over a given time. The lower the release (leaching) rate,the lower the biocide's aquatic toxicity and the longer the period oftime that the biocide is effective for a given amount of biocideoriginally present in the coating. The present embodiments thereforemake this release rate as low as possible.

The Higuchi Model of release (leaching) rates of a compound into anaquatic medium informs the selection of biocides forming thecompositional embodiments of this invention. The equation that governsthe release rate is

RR=√{square root over (2DSe(A−0.5Se)t)}=√{square root over (K _(h) t)}

where RR is the release rate or amount of drug released in a time periodt for the area exposed to water, usually expressed in μg/cm2/day orng/cm2/day, D is the diffusion coefficient characteristic of the biocidethat gives an indication of how rapidly a chemical compound willdiffused from a region of high concentration to a region of lowconcentration and which is inversely related to the molecular weight andvolume of the molecule, S is the aquatic solubility of the biocide, e isthe porosity of the matrix (polymer in the present invention), A is theconcentration by weight of the biocide expressed as a biocide density orweight of the biocide per cc3 of matrix, also known as the loadingfactor, e is the porosity of the matrix, and Kh is the Higuchi releaserate constant of the Higuchi Model.

The leaching rate is proportional to the product of the Kh factor andthe square root of the time exposure. For the purpose of this invention,the water solubility of the biocide, S, should be as low as possible(<20 mg/L), the diffusion constant, D, should be as small as possible,which correlates with as high a KOC as possible, which in turncorrelates with as high a molecular weight and molecular volume aspossible, with such a preferred biocide being much less likely todiffuse out of the matrix (the polymer coating in this invention). Alsothe porosity of the matrix, e, should be as low as possible which, for apolymer coating (and especially for flourourethanes) would be extremelylow, and a loading factor concentration of the biocide within thematrix, A, should be as low as possible. The more potent a biocide is,the lower the loading factor concentration in the polymer matrix can befor a given effective lifetime, which also is of economic advantage aswell as the fact that, if A is too high, the mechanical, chemical, andcuring properties of the polymer could be adversely affected. The lowerKh is, the better the biocide is for the purposes of the presentembodiments.

As an example, a low solubility biocide such as ivermectin results in arelease rate between about 0.7 and about 3.0 ng/cm2/day (depending uponif the ivermectin was dissolved in an organic solvent or not,respectively) as compared to the release rate for copper in copper-basedbottom paints of several μg/cm/cm2/day—roughly 30,000 times greater.With copper based bottom paints, the copper biocide is released overlarge areas the size of the ship's hull, whereas the ivermectinconcentration in the outer biostatic polymer layer is very low, so whilethe relative concentration of ivermectin in the inner biostatic polymerlayer is high, that inner biocidal polymer layer is shielded from theaquatic environment and the ivermectin leaching rate into the aquatic isvirtually nil, at least millions of times less than with copper-basedpainted hulls. Furthermore, if a biostatic biocide like cupro-nickel isused in the outer polymer layer, where the measured aquaticconcentration of copper ions is less than the limits of detection of 50ppb (0.05 mg/L), under this circumstance, the Higuchi Model Release Rategoes essentially to zero. In fact, with the choice of such low watersolubility biocides, low porosity polymer layers, high KOC adsorptioncoefficients (low diffusion constants), in all the embodiments of thepresent invention to be described the Higuchi Model Release Rate goesessentially to zero, so that the operating effective life time of theanti-fouling coating of the present embodiments is greatly prolonged notonly by the very high durability of the polymer coatings, but also theextremely low release rate of the biocides into the aquatic environment,which also greatly diminishes the chances for undesirable effects onthat environment.

With respect to undesirable effects on the aquatic environment and thebenign and beneficial organisms that reside there, the outer biostaticlayer is less potentially hazardous both for the chemical and physicalreasons mentioned above and shields the water from contact with the morepotentially hazardous inner biocidal layer. Also, when an occasionalbarnacle or mussel larva penetrates the outer layer and touches theinner layer as a juvenile, it is killed quickly and outright on contact.It has been experimentally observed that, when a polymer impregnatedwith a biocidal biocide such as ivermectin is exposed to barnacle ormussel larvae, and there is no outer biostatic attachment inhibitingpolymer layer present, that larvae do attach regardless and grow on thesurface of the polymer layer. The organisms with their tiny shells canbe seen with a magnifying glass. However, no adult barnacle or musseladults are seen weeks or months later, because the young juveniles arekilled quickly as soon as the juveniles pierce the outer surface of thebiocide impregnated polymer. With the present embodiments, the area ofthe puncture site of the inner layer is microscopic and thus nothingleaks out of the inner layer into the surrounding water.

The effective diffusion coefficient, D, of the biocidal biocides as wellas the leaching area, S, of the inner biocidal layer are essentiallyzero, showing that the Higuchi Model Release Rate of the biocides in theinner layer is essentially zero. Thus, even TBT can be used within theinner polymer layer. There is no release of potentially hazardousinner-layer biocide other than through tiny microscopic pits withdiameters of about 0.1 mm (the size of the juvenile barnacle or musselthat produced that pit) in the outer biostatic polymer layer. The areaof that exposure of the inner biocidal polymer layer to the aquaticenvironment for a defect 0.1 mm in diameter is 0.00157 mm2 or 1.57×10−5cm2 per barnacle or mussel for the few organisms that manage to attachand pierce the outer biostatic polymer layer and reach the surface ofthe inner biocidal polymer layer. Compared to the typical biocides oftoday's soft ablative or hard leaching paints that leach their biocides,copper and otherwise, into the aquatic environment over an area as largeas the boat's hull, the beneficial effects of the present embodiments onthe aquatic environment are significantly improved.

One further benefit of the present embodiments, namely the shieldingeffect of the more potent biocidal laden biocidal Polymer-I inner layerby the outer biostatic Polymer-O layer, can be discussed in terms of theHiguchi Model. The model can be applied to each layer in turn. Thedescription so far of the model corresponds to the situation for theouter bio static Polymer-O layer. The Higuchi Release Rate Constant Khfor each layer is for a given impregnated biocide in that layer and isstrongly dependent on D, the diffusion constant of the biocide. Applyingthe Higuchi Model to the outer biostatic polymer-O layer, for eachbiocide in the outer biostatic polymer layer, the effective life of thatbiocide can be estimated to be the length of time it takes for 70% ofthe biocide leaches out, which determines the useable life of the of theouter coating to effectively repel barnacle and mussel larvae andprevent them from settling and attaching. For a given solubility of thebiocide, S, loading biocide concentration, A, and porosity, e, of thepolymer matrix, the period of antifouling effectiveness of the outerbiostatic polymer-O layer will depend upon the diffusion constant, D, ofthe biocide. The effect of all the biocides present in the outer layeris a weighted average of these factors for all the biocides in thelayer, including the average diffusion constant of each biocide. Theaverage D of all the biocides in that layer should be as low aspossible, both for the benefit of the environment, and for extending theeffective operating life of the coating as long as possible. Hence theneed for biocide molecules of high molecular weight, preferentiallyabove 200 Daltons (molecular weight) and large molecular volume withcomplex molecular structure.

Applying the Higuchi Model to the more potent and potentially moreenvironmentally unfriendly inner biocidal Polymer-I layer, because thatlayer is effectively shielded from the aquatic environment, these morepotent biocides cannot leach out into the water. The average diffusionconstant for all the biocides in the inner layer is essentially zerobecause they are blocked from leaching out by the outer layer. Thus evenfor the most toxic biocide known, TBT, if the Polymer-I layer wereimpregnated with this compound, the diffusion constant will still beeffectively zero, the Higuchi Release Rate Factor would be essentiallyzero, and the environment would remain completely protected.Furthermore, a second beneficial effect occurs that, after severalyears, when all of the biocides in the Polymer-O layer finally haveleached out, and larval forms can no longer be prevented from attachingand settling, the Polymer-I layer will still be intact capable ofkilling the juvenile biofouling organisms on contact as soon as theypierced the boundary between the Polymer-O and Polymer-I layers. Anadditional period of useable antifouling time thus elapses before thePolymer-I will fail, not because of leaching out of the biocides in thatlayer, but rather because the continued dying of juvenile forms on thatlayer will eventually cause a mass of dead juveniles on the surface ofthe coating in the form of a layer that will make it impossible forfurther arriving biofouling juveniles to get into contact with thebiocides of the Polymer-I layer, such that a biofouling mass will beginto grow as these later arriving larval forms are allowed to settle,progress into juveniles, and adult animals, thus causing coatingfailure. The structure is stripped and repainted to avoid permanentirreversible corrosion and other damage to its surface.

The term capsaicin, as used herein, indicates any of the alternativecapsaicin-related compounds. The term ivermectin, as used herein,indicates any of the alternative ivermectin-type compounds. The termspyrethrin and pyrethrinoid indicate any of the alternative pyrethrin orpyrethrinoid type of compounds. Metal pyrithione salts refer to any ofthe alternative algaecides (herbicides) listed in the table of FIG. 21C.The term biocidal biocide indicates any biocidal insecticides ormiticides listed in the tables of FIG. 21A and FIG. 21B or the naturalplant alkaloid biocides listed in the table of FIG. 21D, as well as anyother insecticide, anti-helminthic, cupro-nickel and related metalalloys, and any human drug such as the tricyclic anti-depressants or anyveterinary drug such as medetomidine that have shown anti-invertebrateanti-biofouling effects either with barnacles, invasive mussels, orshipworms and other calcareous bio-foulers, may be used as a componentbiocide in this invention, that referring to a polymer indicates thatany plastic or non-plastic polymer in the previously defined list ofpolymers may be used as a component polymer in this invention, and thatreferring to a polymer primer indicates that any polymer primer in thepreviously defined list of polymer primer list may be used as acomponent polymer primer in this invention, with the specific exclusionof the non-polymer compound, zinc chromate, which is being excluded fromuse as a primer compound from this invention because of its humantoxicity and carcinogenicity. The distinguishing features of the presentembodiments are not determined solely by the specific biocide used inthe invention, but rather it is the specific process of sequesteringvarious biocides of a plurality of one or more of such biocides within amolecular and mechanical structure of multiple specific polymer layersthat comprise a multi-layer polymer anti-fouling coating possessing adifferent biocidal concentration and composition as a function of depthand location within the anti-fouling coating so as to firstly, inhibitthe growth and proliferation of biofouling organisms by inhibiting thesettlement, adhesion, and attachment by multiple simultaneous biostaticand biocidal means of fouling organism larval forms by an outer firstpolymer layer of biostatic nature located in the outer layer of theanti-fouling coating adjacent to the water touching that coating andcontaining a first biocide composition, and then sequentially, andsecondly, inhibiting the growth and reproduction by effecting a killingon contact of these organisms at the juvenile stage by multiplesimultaneous biostatic and biocidal means of a second type ofcomposition within an inner polymer layer of biocidal nature in theinner portion of the anti-fouling coating adjacent to the surface beingprotected, as well as allowing for the use of an inner polymer primer,if necessary, to enhance the adhesion of the inner polymer layer to theprotected surface as well as an outer polymer primer, to enhance theadhesion, if necessary, of the inner polymer layer to the outer polymerlayer. The need to use either an outer or inner primer polymer layerswill depend the need to increase the adhesion between the inner biocidaland outer biostatic polymer layers or between the inner polymer layerand the surface being protected, which in turn will depend upon theproperties and surface compatibilities of the polymers being used, theproperties of the surface that is being protected, the nature of thesurrounding water and its turbulence, and whether the surface isrelatively still or moving at a high velocity relative to the water.

The taxonomy of hard biofouling organisms, when analyzed forsimilarities and differences, can predict certain commonalities thatwill allow a poly-pharmotherapeutic approach to their prevention,control, and eradication. Because barnacles are both members of thearthropod phylum and the crustacean subphylum, certain classes ofchemicals that include insecticides and anti-helminthics will kill themas they would insects, and parasitic worm infestations in humans andanimals. However, because they are also crustaceans, such chemicals, ifthey can kill barnacles, they can potentially kill desirable crustaceansin the aquatic environment such as lobsters, crabs, crayfish, andshrimp. Hence, the existence of the need for any insecticide oranti-helminthic that can control barnacles or mussels must be virtuallywater insoluble so that only the barnacles and mussels and no otherorganisms in the aquatic environment away from the application of thebiocide at the site of barnacle infestation are harmed as well. One suchbiocide representative of compounds that can fulfill these requirementsis the anti-helminthic Ivermectin which permanently paralyzes thenervous system of the barnacle by activation of certain membrane ionchannels and it acts as a neuromuscular blocker like atropine poisoningwhich induces hyperpolarization of these animals' nerve cells.Ivermectin is a large molecule macrocyclic lactone derived fromStreptomyces avermitilis with anti-parasitic activity. It has twostructurally related compounds, ivermectin B1A and ivermectin B1B thatare present in a 4:1 ratio mixture that is sometimes referred to asavermectin. Ivermectin exerts its anthelmintic effect via activatingglutamate-gated chloride channels expressed on nematode neurons andpharyngeal muscle cells. Distinct from the channel opening induced bythe glutamate nerve transmitter, ivermectin-activated channels open veryslowly but essentially irreversibly.

As a result, neurons or muscle cell membranes remain in a hyperpolarizedstate that does not allow the transmission of nerve electrical impulses,thereby resulting in paralysis and death of the parasites. Neuromuscularblockade has been effective against virtually all species of the PhylumArthropoda, Subphylum Crustacea, which includes all barnacle andinvasive shrimp and crab species as well as species of the PhylumMollusca, Class Bivalvia, which includes quagga mussels, zebra mussels,Mediterranean mussels, and shipworms. Ivermectin, because of its the lowwater solubility and the predictions of the Higuchi Model, protectsbenign and commercially beneficial crustacean and mollusk populationslocated away from the protected surface. Ivermectin does not readilypass the mammal blood-brain barrier to the central nervous system whereglutamate-gated chloride channels are located. As a result, theparasitic hosts are relatively resistant to the effects of this agent.This pharmaceutical agent has been found to be effective against shellforming biofouling organisms, as well as a broad class of parasiticworms and larvae in humans and animals, lice and mites in variousenvironments, and it is virtually water insoluble. The various moleculesthat make up the ivermectin class of drugs (Avermectin, Abamectin,Moxidectin, Selamectin, etc.) do not contain any chlorine atoms, as theywere originally derived from a soil bacteria, and thus do not possessany of the toxicity presented to the aquatic environment generallyassociated with chlorinated hydrocarbons. These molecules also breakdown quickly due to the effect of ultraviolet light from sunlightpermeating the water.

Another pharmaceutical agent that takes advantage of the common trendsfound in different taxonomic groups of biofouling organisms is theanti-fungal agent, lufenuron. It is an agent that deactivates animportant enzyme, chitin synthetase, responsible for the production ofchitin in insects, mites, lice. Furthermore, the since the proteinmatrix upon which calcium is laid down to form shells in quagga andzebra mussels, and barnacles, as well as the calcium exoskeletons ofshipworms (marine wood borers), attaching calcareous bryozoans, andinvasive shrimp and crab species is the same chitin that forms theexoskeleton of insect and arachnid arthropods, all of these animals willbe beneficially destroyed by lufenuron. These hard fouling organisms areall killed by lufenuron because they cannot form and/or enlarge theirshells and calcium exoskeletons because they cannot form the chitinframework of these shells to allow calcium deposition, and they die ofexposure or by other mechanisms.

Beneficial crustaceans also contain chitin, including lobsters, shrimps,crabs, and cray fish among others, and can find the use of ananti-chitin, anti-fungal in the aquatic environment highly toxic.However, lufenuron, is water insoluble, and thus it renders its toxicreaction only to a susceptible organism directly in contact with it,rather than to other animals in the aquatic environment, because itcannot leech out, dissolve, and be transported away to other locationscontaminating the environment. The maximum water concentrations oflufenuron are below the toxicity levels of these desirable organisms.Lufenuron is a chlorinated hydrocarbon with two chlorine atoms, which asa class of compounds as pointed out previously, is generally toxic tothe environment in varying amounts depending upon the chemical. As notedabove, however, the water insolubility caused by the presence of 8fluorine atoms in lufenuron's molecule, plus other measures describedherein, keep the biocides within the chemical coating and not in thewater, making this agent safe for the aquatic environment.

Direct contact by the invasive biofouling organism with a biocidalbiocide impregnated in a coating, rather than release of biocides intothe water, is the best manner by which the calcareous animal can bekilled. Killing the organism while it is still in a juvenile form,before it proliferates, will prevent the spread of such invasivespecies. Multiple biocides within each layer of the coating makes itless likely that resistance to the biocides will develop.

Pesticides that can accomplish direct and immediate cell killing areknown as biocidal biocides. However, it can be shown that invasivecalcareous species, such as barnacles, quagga and zebra mussels,shipworms, and calcifying bryozoans can be controlled by a secondmechanism, namely by preventing attachment of biofouling larval forms tothe threatened surface. This is effective because attachment isnecessary for further growth and maturation into the burrowing juvenileform. There are chemical agents that can prevent these biofoulingspecies from attaching to the target surface. This attachment ofinvasive calcium-forming species is mediated by microscopic larval formssuspended and traveling in the water (veligers for quagga mussels, zebramussels, Mediterranean mussels, and ship worms, and cyprids forbarnacles as examples). These larval forms need surfaces to survive andgrow. If the animal is inhibited from attaching to the surface, then theanimal will not only not attach to the target surface and be repelledfrom it, its life cycle will also be interrupted and it will die withintwo or three weeks after running out of stored nutrients unless it canfind a suitable alternative place for attachment. Since such a biocidedoes not kill the organism directly on contact, but instead onlyprevents growth and proliferation and a possible delayed death, thepesticide is considered to be a biostatic biocide rather than a biocidalbiocide. This distinction between biostatic biocides and biocidalbiocides will be used throughout the present description.

A common food supplement, capsaicin, which is a natural plant alkaloidand an extract of the chili pepper, Capsicum annuum, has the property ofbeing very irritating to the swimming larval forms and will repel themif they alight on a surface coated with a polymer impregnated withcapsaicin. This food supplement, normally used to increase the spicyheat sensation of food, has been shown to be able to retard barnaclegrowth and attachment and thus kill them indirectly, but does not killthese organisms directly. Hence capsaicin is a biostatic biocide.

However, although capsaicin is biostatic, it nevertheless has been quitesuccessful in repelling these organisms before they attach in theirlarval state, and it has the added benefit of being totally waterinsoluble. Thus its chemical leaching rate is very low, allowing for aprolonged effective operational life. Capsaicin further has no known illeffects on benign and beneficial aquatic organisms. It contains noundesirable chlorinated hydrocarbon structures. Capsaicin is anincredibly stable plant alkaloid that is insoluble in water (13 mg perliter, at 30° C.) and, in its pure form, is extremely powerful in itseffect. It is unaffected by heat or cold and it retains its originalpotency over extended periods of time, through cooking and freezing.Pure Capsaicin equals 16 million SHU and most purified Capsaicinextracts of chili peppers, 95% Capsaicinoids and 5% other substances byweight, will contain by weight 69% Capsaicin (SHU 16 million), andrelated alkaloids, 22% Dihydrocapsaicin, (SHU 15 million), 7%Nordihydrocapsaicin, (SHU 9.1 million), 1% Homodihydrocapsaicin, (SHU8.6), and 1% Homocapsaicin, (SHU 8.6 million) which calculates out for a95% pure chili pepper extract, as used in the present invention, aScoville Heat Unit rating of 14.3 million SHU as compared to the pureCapsaicin of 16.0 million SHU. Because of the need to keep any bioactiveagents impregnated into a polymer coating free of any significantimpurities, either pure capsaicin, or a 95% chili pepper extract may beused.

Organic impurities are detrimental to the use of capsaicin as a biocidalantifouling repellant because of undesirable breakdown of such organicimpurities within the polymer coating. This may cause undesirablechemical and physical changes in the integrity of the polymer layerincluding discoloration, changes in the curing process, and loss ofphysical imperviousness to water. The purity concerns that apply tocapsaicin also apply to the addition of any biocide or biostatic to anypolymer layer, no matter what the biological agent might be, and thusonly pure versions of any biological agent should be used.

The general structure of the present embodiments includes a polymerstructure of an outer polymer layer and an inner polymer layer thatoptionally has an inner polymer primer between the inner polymer layerand the surface to be protected, and optionally an outer polymer primerbetween the inner polymer layer and the outer polymer layer. The outerpolymer layer contains a mixture of biocides that gives that layer abiostatic function with respect to inhibiting the attachment and growthof larval and juvenile forms of biofouling organisms, while the innerpolymer layer contains a mixture of biocides that gives that layer abiocidal function with respect to killing any immature biofoulingorganisms that manage to penetrate the outer polymer layer. Furthermore,the outer polymer layer also may be impregnated with an herbicide aswell to inhibit plant biofouling organisms. Further embodiments of thetwo-layer polymer structure allow optionally for biocides to beintroduced in either the inner or outer primer polymer layers, or both,if primers are needed to improve the adhesion of certain outer layerpolymers to the chosen inner layer polymer or to improve the adhesion ofcertain inner layer polymers to the particular material of the surfaceto be protected. Hence, the primers themselves can participate in theanti-fouling function of the coating. Also, to increase the durabilityand adhesion of the polymer primers, their composition may includeparticulate matter including fragments of stainless steel, silica, cubicboron nitride, industrial diamond powder, carbon fiber, carbides ofboron, metals and silicon, with a preferential embodiment using boroncarbide, as well as any pigment particles that would give such layerscolor. Such particulate matter may be introduced along with the biocidesin both the inner and outer polymer layer as well to improve theirdurability and resistance to abrasion.

With this specified mechanical and molecular structure and thisspecified composition, which varies within the anti-fouling protectivecoating depending upon the location of the specified polymer layer inthe antifouling coating, a sequential process is created of control,inhibition, prevention of attachment and proliferation, and killing ofthe biofouling organisms on contact with the inner biocidal polymerlayer. The different steps in this process occur at different siteswithin and on the multi-layer polymer coating.

Cytotoxic cell killing biocidal biocides are not in direct contact withthe aquatic environment, but rather are contained in an inner polymerlayer (Polymer-I) that is covered by an outer polymer layer (Polymer-O)with less potent, biostatic biocides. The outer polymer layer interfaceswith the aquatic environment and prevents attachment of biofoulingorganism larvae forms (cyprids and veligers), thereby repelling them.Direct, on-contact cell killing is done by the inner biocidal polymerlayer (Polymer-I) of the antifouling coating only when the smallminority of remaining larvae that were not repelled by the outer layerhave just undergone metamorphosis to juvenile organisms to penetrate theouter biostatic polymer layer (Polymer-O) to touch the inner biocidalpolymer layer. This vastly diminishes the number of dead, calcifiedinvertebrate animals that collect on the antifouling coating with time.This is extremely beneficial, as with prior antifouling coatings, eachand every organism that touched and settled onto the protected surfaceeither grew or died on the surface of the coating. Thus, with theprevious antifouling coatings, to be effective, virtually all foulinganimals would need to die.

While the organisms are indeed dead, however, their shells could serveas perfect sites for attachment of successive arriving organisms, sitesthat are nowhere in proximity to the biocide in the coating, therebyensuring the survival of the new arrivals, and thereby ensuring theeventual failure of the prior art coatings. As a result, those coatingsin general antifouling coatings last only one or two seasons.

While the outside layer of the present embodiments may be disrupted bythe few larval forms that might be resistant to the biocides in theouter biostatic polymer layer, the defect in the outer polymer layerproduced by the developing, microscopically sized larval and juvenileforms, no larger than 0.1 mm, is negligible. Likewise, the defect in theouter surface of the inner biostatic layer caused by the penetration ofthe ring-like edge of the early juvenile shell is of similar microscopicsize, because the organism is killed upon contact with the innerbiostatic layer while it is still small. As a result, both the outsidebiostatic polymer layer and especially the inside biocidal polymer layerremain largely intact. This immunity to damage from attaching invasiveorganisms, results in continued complete shielding of the inner biocidalpolymer layer from any significant exposure or contact with thesurrounding aquatic environment. Chemical leaching is prevented and theconfinement of the more potent and more potentially hazardous biocidalbiocides within the biocidal polymer membrane is maintained.

This structural arrangement of polymers leads therefore to increasedsafety to benign and beneficial organisms within the surrounding aquaticenvironment as well as a much greater lifetime because of the preventionof chemical leaching of the inner biostatic layer's biocides into theenvironment. In this manner, even the highly toxic biocide, TBT, andless toxic metallic biocides like copper and zinc salts and metals, canbe safely contained within the inner biocidal polymer coating and awayfrom the surrounding aquatic environment.

The purpose of having a biocidal biocide in relative low concentration,together with a biostatic biocide in relative high concentration, in theouter biostatic polymer layer in a preferred ratio of about 1:10 is 1)to give an enhanced, synergistic inhibiting biostatic effect onattachment by invertebrate larval biofouling organisms and, 2) toproduce this enhanced inhibitory biostatic effect without the need for ahigh concentration of biocidal biocides in the outer biostatic polymerlayer which might have a higher probability of producing an adverseeffect on the surrounding aquatic environment and its benign andbeneficial organisms.

However, a second biostatic biocide in sufficiently high concentrationsmay replace the biocidal biocide in low concentrations in the outerbiostatic polymer layer. The purpose of having a biostatic biocide inrelative low concentration together with a biocidal biocide in relativehigh concentration in the inner biocidal polymer layer in a preferredratio of about 1:10 is 1) to give an enhanced, synergistic organismkilling on contact biocidal effect on invertebrate biofouling juvenileforms that managed to develop from larval forms that include veligersfor mussels and cyprids for barnacles that in turn managed to attach anddevelop piercing the outer biostatic polymer coating in spite of itsbiostatic effect, and 2) the biostatic component to organism killing isless important to the inner biocidal polymer layer to prevent attachmentto the outer biostatic polymer layer. Nevertheless, its presence doeshelp reduce the amount of biocidal biocide needed because of itssynergistic effect with the biocidal biocide.

A second biocidal biocide in sufficiently high concentrations mayreplace the biostatic biocide in relatively low concentrations in theinner biocidal polymer layer. The range of the ratio of the biocidalbiocide concentration to the biostatic biocide concentration in theouter biostatic polymer layer may range from about 1:1 to about 1:1000,with a preferred ratio being about 1:10 and the range of the ratio ofthe biostatic biocide concentration to the biocidal biocideconcentration in the inner biocidal polymer layer may range from about1:1 to about 1:1000, with a preferred ratio being about 1:10.

Exemplary biostatic biocides used in the outer biostatic polymer layerinclude ultra-pure capsaicin in a concentration ranging from about 0.01%to about 50% by weight, with a preferred range of about 0.1% to about10%, cupro-nickel alloy powder (about 90% copper and about 10% nickelwith trace amounts of iron and manganese) with a concentration rangingfrom about 0.01% to about 50% by weight with a preferred range of about0.1 to about 10%, and low dose pyrethrin class of compounds in aconcentration of about 0.01% to about 0.5%, with a preferredconcentration of about 0.1% to about 0.5%. However, a suitablesubstitute may be made from the list of natural plant alkaloids listedin the table of FIG. 21D, which includes those alkaloids known to beeffective against insect pests.

Exemplary biocidal biocides used in the inner biocidal polymer layerinclude ivermectin and similar chemical analogs used in a concentrationof about 0.01% to about 50,% with a preferred range of about 0.1% toabout 5%, lufenuron, in a concentration of about 0.01% to about 50%,with a preferred range of about 0.1% to about 5%, and high dosepyrethrin class of compounds in a concentration from about 0.5% to about5% with a preferred concentration of about 0.5% to about 1%, togetherwith the pyrethrin potentiating metabolism inhibitor, piperonyl butoxideused at a concentration of about 1% to about 10%, with a preferredconcentration of about 4%. However, a suitable substitute may be madefrom a list of insecticides listed in table FIG. 21A or from a list ofmiticides listed in table FIG. 21B., as well as miscellaneous compoundslike the human medications amitriptyline and imitriptyline and othermembers of the class of tri-cyclic depressants, and variousanti-helminthics including albendazole and its low water solublechemical analogs.

Any known chemical agent that has been observed to have activity againstcalcareous biofouling invertebrate organisms are suitable for and wouldfall under the purview of the current invention, provided the compoundadheres to the toxicity, leaching, and solubility requirements of theapplication.

A high strength particle additive used to enhance adhesion of thepolymer primer and enhance durability of either the polymer primer oreither the inner biocidal polymer layer or the outer biostatic polymerlayer may include boron carbide. However, a suitable substitute may bemade from a group that includes high-strength metal particulates, suchas stainless steel and titanium (on non-metallic surfaces only toprevent unwanted galvanic corrosion), fiber materials such as aramidfiber, fiberglass and carbon fiber, minerals such as silica, fluorspar,or carborundum, and industrial diamond powder, or ceramics such as boroncarbide, metal carbides, silicon carbide, and cubic boron nitride. Theparticle size can range from less than about 1 micron (approximately<12,000 mesh) to about 100 microns (approximately 150 mesh) with apreferred size range of about 20 microns (approximately 530 mesh) toabout 50 microns (approximately 270 mesh). The concentration of suchadditives can range from about 0.01% to about 50%, with a preferredrange of about 1% to about 15%.

The frictional properties of the outer biostatic Polymer-O can bepreferentially and favorably reduced by the addition of low-frictionadditives such as molybdenum disulfide powder, non-cubic boron nitride,silicone powder, PTFE powder, graphite flakes, and graphenenanoparticles. To enhance the friction-reducing effects, extremely smallparticle sizes of less than about 20 microns would be beneficial, with apreferred size of less than about 1 micron.

Embodiments that include an algaecide added to the outside biostaticpolymer layer may use a metal salt of pyrithione, either zinc, or zincmixed with either barium or silver in a concentration by weight of about0.1% to about 20%, with a preferred range of about 1% to about 10%.However, a suitable substitution may be made from the selectedherbicides listed in the table of acceptable herbicides of FIG. 21C.These lists of potential components to the composition of this inventionare not meant to be exhaustive and it should be understood that otherappropriate materials may be used instead.

When delineating the class of biocides effective against barnacles andmussels, it is to be remembered that barnacles are crustaceans, andcrustaceans are arthropods. Insects are also arthropods. Therefore, anypesticide that is an insecticide that possesses effectiveness againstarthropods will also be effective against barnacles, though somevariation in efficacy might be expected. It is to be also noted thatbarnacles produce chitin like insects do, only that barnacles use it toact as scaffolding upon which they deposit calcium to form and growtheir shells. Thus a biocidal biocide, the chitin synthetase enzymeinhibitor lufenuron, that is toxic to sea lice and other insects wouldalso be toxic to barnacles, for when barnacles cannot produce chitin,they cannot produce their shells.

It is also to be noted that, although mussels belong to the nextprimitive animal phylum, Mollusca, just below the evolutionary positionof Arthropoda, and given that virtually any chemical substance that hasbeen effective against barnacles have also worked against mussels, anybiocide that shows effectiveness against arthropods will showeffectiveness against invasive mussels. The reverse has also been shownto be true, namely that any biocide likely to show activity againstinvasive mussels will show activity against barnacles, given that theirnervous systems and cell membrane receptors are similar and close toeach other on the evolutionary scale.

Thus any biocide active against arthropods will be active againstmussels, and any biocide that is effective against mussels, willtherefore be effective against arthropods and, as a result, crustaceans,and hence barnacles, though some variation in efficacy is possible.Mussels, like barnacles, require the production of chitin for theirshells and will die of dehydration if exposed to a chitin synthetaseinhibitor such as lufenuron. Both the larval form, veligers, that arecommon to zebra, quagga, and Mediterranean mussels, and the larval form,cyprids, that are part of the barnacle life cycle, have GABA-a receptorson their nervous system which allows both of them to be repelled fromattachment on surfaces containing chemical compounds that are GAB A-areceptor modulators, such as capsaicin. Indeed, capsaicin will inhibitattachment of larval biofouling forms of both barnacles and mussels. Thepresent embodiments make use of these intertwined taxonomic,physiologic, and metabolic relationships common to both mussels andbarnacles, and other calcium forming biofoulers as well, to enhance thebio-toxicity to invasive mussels and barnacles through the use ofmulti-drug poly-pharmacotherapy. This intricately related arrangement ofmultiple polymer protective layers, with a biostatic arrangement ofbiocides on the outside of the coating and a biocidal arrangement ofbiocides on the inside of the coating, a composition that varies withthe depth of the protective polymer coating and the layer in thatpolymer coating, will be a common feature of the present embodiments. Atleast two categories of embodiments are described: the first relating tothe structure and function of the antifouling coating itself, and thesecond relating to applications to which this anti-fouling coatinginvention may be applied. The applications fall into seven classes ofmarine and freshwater anthropogenic (man-made) objects susceptible tobiofouling: 1) Vessels, water conduits, and transport equipment; 2)Navigational and instrumented buoys and equipment; 3) Stationarystructures including buildings, piers, bridges, pilings, sea walls, oilplatforms, and bulkheads; 4) industrial pipelines, water intakes, powerplant intake inlets, and filters; 5) Fixed submerged surfaces; 6)Flotsam, debris, and wrecked structures including historical shipwrecks;7) Non-vessel operating machinery submerged in water. Additionalapplications involving filters, fishnets, fiber and rope, wave energyharvesting equipment, sea water electrolysis equipment, and enginecooling systems will also be described. It should be understood thatthis list is meant to be illustrative only and should not be construedas limiting.

Referring to FIG. 1A, a two-layer polymer structural embodiment of thebiofouling coating is shown where the outer biostatic polymer layer 3 isadjacent to, and to the right of, inner biocidal polymer coating 9. Theleft hand side 1 is exposed to the aquatic environment 2. Biocidalbiocide 4 is present in relatively high concentration in inner biocidalpolymer layer 9 and in relatively low concentration in outer polymerlayer 3. Any appropriate biocidal biocide, as described above, can beused. The Biostatic biocide 5 is present in relatively highconcentration in outer biostatic polymer layer 3 and is present inrelatively low concentration in inner biocidal polymer layer 9, whichcovers the surface to be protected 6. The surface 6 may represent metal,wood, plastic polymer, non-plastic polymer, ceramic, and so forth. Inthis embodiment there is no primer used between the inner biocidalpolymer layer 9 and the protected surface 6 or between the innerbiocidal polymer layer 9 and the outer biostatic polymer layer 3.

Referring to FIG. 1B, a structural polymer layer embodiment of thepresent invention is shown where the following susceptible biofoulingsattached to the water surface of Polymer-O: algae 10, bryozoan 11,mussel 12 (and from this point, mussel will refer to the three invasivespecies that most concern this invention, the quagga mussel, the zebramussel, and the Mediterranean mussel), fungi 13, biofilm 14 (containingan organic protein matrix and bacteria), and barnacle 15. All of theseorganisms are seen attached to the left side exposed to water, labeledas water 2 in FIG. 1A, the water side of Polymer-O. Polymer-O 3 andpolymer-I 9 are as in FIG. 1A and the protected surface 19 is shown.There is an outer polymer primer (Primer-O) 18 between Polymer-I andPolymer-O, and the Primer-O contains biostatic biocide 16 (5 on FIG. 1A)and biocidal biocide 17 (4 on FIG. 1A) in equal concentrations, althoughthe ratio of the concentration of the biocidal biocide to the biostaticbiocide in primer-O can range from 1:10 (similar to Polymer-O) to 10:1(similar to Polymer-I). All biostatic biocides and all biocidal biocidesmay again be members of the classes of biocides defined in thedisclosure and the tables of FIGS. 21A, B, and D and will hold truethroughout all of the embodiments so described.

Referring to FIG. 1C, a structural embodiment of the present inventionis shown containing a four-layer structure: Polymer-O 3, now labeledwith several constituent coatings 20 that were applied separately tobuild up the thickness of the polymer-O layer, Polymer-I 9 now with twoseparate coatings 24 that were used to build up the thickness of thepolymer-I layer, a Primer-O 21, and a new inner polymer primer 22.Polymer-O 3, Polymer-I 9, and Primer-O 21 contain biocides as previouslydescribed for FIGS. 1A and 1B. The surface being protected is designatedas 23. Coating boundaries 25 and 26 are shown between successivecoatings making up Polymer-I 9 and Polymer-O 3 respectively. Biostaticbiocide 4 and biocidal biocide 5 are as previously in the previouslydescribed concentrations. The biofouling organisms in the body of water2 are again seen attached to the water surface 1 of Polymer-O. Coatinginterfaces 25 and 26 are only theoretically present if the coatings wereadded while the previous coatings were still tacky and semi-cured. Theinterfaces would disappear under these conditions and the separatecoatings would fuse into one inseparable layer comprising the respectiveinner and outer polymer materials. However, if each coating iscompletely dry and cured at the time of the next coating, theseinterfaces would structurally remain.

In this manner, the Polymer-I and Polymer-O layers 3 and 9 can be builtup in a layered or fused manner to be of arbitrary thickness, with apreferred thickness that ranges from about 5 mils to about 200 mils.Each incremental coating that builds up the polymer layer can be about10 to about 20 mils, depending upon the viscosity and other physicalcharacteristics of the polymer. Since a primer usually only requires anapplication of one layer, the thickness of the inner Primer-I coating 22and the outer Primer-O 21 would be in accordance with the recommendedthickness for the primer polymer being used. Note that, if surface 23 ispart of a steel structure that is thicker than a sheet structure andmore massive, the optimal primer for greatest durability of the Primer-Ilayer 22, and thus the entire anti-fouling coating, may be a zinc-richprimer having an inorganic zinc compound such as zinc phosphate or zincsilicate or an a zinc enriched epoxy, the latter being an epoxy primerimpregnated by weight up to 90% with zinc powder. Zinc chromate may bespecifically excluded from this embodiment because of its toxicity.

Referring to FIG. 2A, a structural embodiment of the anti-foulingcoating is shown where the outer biostatic polymer layer 3 (Polymer-O)and the inner biocidal polymer layer 9 (Polymer-I) are fused together asone layer because polymer-O 3 was painted over Polymer-I 9 while thelatter was still incompletely cured and was still tacky, in the samemanner that several coatings may be used one after another beforecomplete curing of the previous coating. 30 represents the fusedinterface between the biostatic-impregnated Polymer-O 3 andbiocidal-impregnated Polymer-I 9. As described above, Polymer-O 3 has arelatively high concentration of biostatic biocide 5 and a relativelylow concentration of biocidal biocide 4 while Polymer-I 9 has arelatively high concentration of biocidal biocide 4 and a relatively lowconcentration of biostatic biocide 5.

Referring to FIG. 2B, a structural embodiment of the anti-foulingcoating is shown where a perforated sheet 31 is inserted into theboundary between Polymer-O 3 and Polymer-I 9 that, together with the twocoatings of polymer, makes up a polymer composite. The perforated sheetof material may be rigid, semi-rigid, or flexible. The perforated sheetor slab of material may be fiber-glass, another plastic, a fabric aramidfiber, a carbon fiber fabric, stainless steel or another metal, nylon,wood, ceramic, and so forth. While the Polymer-I layer 9 is still liquidand not cured, the perforated sheeting 31 is pushed into and immersedinto Polymer-I 9. Polymer-I 9 is allowed to partially cure. WhilePolymer-I 9 is still tacky, liquid Polymer-O 3 is poured over theperforated sheeting 31, through which it flows up against partiallycured Polymer-I. Both polymer layers are allowed to harden and cure,resulting in a fused interface 30 that runs through the perforatedfiberglass sheeting whose inner half is immersed in Polymer-I 9 andouter half is immersed in Polymer-O 3.

Assembling this bi-laminate structure directly on the surface to beprotected, with each layer of the bi-laminate structure containing twobiocides whose concentration depends on the depth from the water surfaceof this structure, distinguishes this embodiment from the simpleassembly of fiberglass composites. Note that the laminate coatings maybe sprayed on, brushed on, poured, or attached to first the protectedsurface and then each other by any other suitable means, and may havepolymer primers added to the process to separate Polymer-I 9 fromPolymer-O 3 if the two polymer layers are sufficiently different thatthere is a need to increase the adhesion between the two layers, as willbe shown in FIG. 2C as Primer-O 21.

If a polymer primer 21 is used between Polymer-O and Polymer-I, theperforated sheeting will either run through the polymer primer, orthrough Polymer-I 9, or through Polymer-O 3. In that case, the assemblyprocess has an added step. Polymer-I 9 is laid down on surface 19. Ifthe perforated sheeting 31 will run through Polymer-I 9, it is thenpushed down into Polymer-I 9 while it is still liquid. If the perforatedsheeting 31 will run through the polymer primer 21 instead, Polymer-I 9is allowed to cure completely, and then the polymer primer 21 is laiddown. While the latter is still liquid, the perforated sheeting 31 ispushed down into the primer 21, which is then cured, followed by layingdown Polymer-O 3. If the perforated sheeting is to run throughPolymer-O, then after the primer 21 is cured or nearly cured, Polymer-Ois laid down and, while Polymer-O 3 still liquid, the perforated sheet31 is pushed down into Polymer-O 3, which is then allowed to curecompletely.

In the case of an outer polymer primer (Primer-O, structure 18 in FIG.1B and structure 21 in FIG. 1C) being used between Polymer-O 3 andPolymer-I 9, where that primer may optionally have the same biocidesimpregnating it as the case for Polymer-I 9 and Polymer-O 3, thattri-laminate polymer structure will resemble the structural embodimentof FIG. 1B, only now with perforated sheet or slab 31 being added. Notethat this assembly process can be further extended to include an innerpolymer primer, Primer-I, structure 22 in FIG. 1C, to produce afour-layer polymer coating as demonstrated by the structural embodimentof FIG. 1C, but with the perforated sheeting or slab 31 being added toany one or more than one of the four layers, Polymer-O 3, Polymer-I 9,Primer-I 22, Primer-O 21 as seen on FIG. 1C.

Referring to FIG. 2C, a structural embodiment of the antifouling coatingof this invention shows a four-layer polymer coating as previouslydescribed in FIG. 1C, with Polymer-O 3 and Polymer-I 9 being comprisedof the same biocides in the same relative concentrations as previousembodiments, but now Primer-O 21, used between Polymer-I and Polymer-Oto promote the adhesion between the two layers as previously describedin FIG. 1C, has biostatic biocide 5, biocidal biocide 4, and also afiller with small sharp microscopic fragments added to it. Theconcentrations of biocides 4 and 5 in Primer-I 22 may be of theconcentrations specified for Polymer-O, Polymer-I, or any ratio ofconcentrations of the two biocides ranging between what was specifiedfor Polymer-I 9 and Polymer-O 3. Therefore, Primer-I 22 can also be madeeither biostatic or biocidal with respect to the invasive biofoulingspecies in aquatic environment 2. Primer-I 22 between the surface to beprotected 19 and Polymer-I 9 is shown also to contain a filler withsharp microscopic fragments added and to contain the same biocides as inPolymer-O 3, Polymer-I 9, and Primer-O 21. Thus Primer-I 22 can also bemade either biostatic or biocidal, but preferentially biocidal as, atthat depth in the coating, the invasive organism must be killed orsurface damage will occur. Biostatic biocides have little use inPrimer-I 22 because, at that point in the antifouling coating depth, soclose to the protected surface, the more potent biocide should be used.One category of metal alloys that are desirable for the purposes of thisinvention, cupro-nickel (and cupro-zinc, cupro-silver) should not beused in any polymer layer that is directly on a metal surface beingprotected because of the risk of galvanic action occurring between thebiocide and a dissimilar metal in the protected surface, which wouldrapidly lead to corrosion and severe damage independent of the corrosionproduced by fouling species. However, on non-metal hulls, cupro-nickelpowder in sufficient amounts would make for an excellent biocidalbiocide in the Primer-I 22. The use of a zinc-rich epoxy polymer primeras an inner polymer primer is biocidal in itself because of the highconcentration of zinc powder present for primer adhesion. The use of azinc-rich epoxy may allow the Primer-I 22 to function as a Polymer-Ilayer, a beneficial arrangement especially on metal surfaces exposed tohigh velocity and turbulence in water, such as ship propellers.

With regard to fillers, in FIG. 2C a first filler 32 is added toPrimer-O 21, a second filler 34 is added to Primer-I 22, and a thirdfiller 33 is added to Polymer-I 9. One purpose of fillers in a polymerlayer or polymer primer, if used, is to promote adhesion between thatlayer and adjacent layers or the surface to be protected, to increasethe wear and durability of that polymer layer and polymer primer, and toincrease their hardness. An adhesion-promoting filler may be one of agroup composed of a metal, such as stainless steel, copper, brass (wherethe percentage of metal fillers would not be high enough to constitute abiocidal agent such as when high concentrations of copper or zinc areused in anti-fouling paint), a mineral, such as fluorspar, silica(silicon dioxide), or industrial diamond powder, or a ceramic, such asboron carbide, cubic boron nitride, silicon and metal carbides, andothers that share extremely high Mohs hardness levels of 9 or greater.

One specific filler that is contemplated herein is boron carbide (BC),B4C (with an alternate chemical structure of B12C3), the third hardestsubstance known, with a Mohs hardness rating of 9.3, next to cubic boronnitride (Mohs 9.5), and diamond (Mohs 10), and it is the preferredfiller because of its low expense, easy availability in a wide range ofmesh particle size, and its effect to improve the mechanical propertiesof the present embodiments. The particle size of the filler may rangefrom about 7 microns to about 90 microns, depending upon theapplication, but certain uses may require nano-sized, sub-micronparticles. The only restrictions on the use of fillers of this type arethat they should not be used with the larger particle size in Polymer-O3, as this would undesirably increase friction from water moving againstthe protected surface, and that fillers used in the polymer layeradjacent to the surface being protected (either Polymer-I 9 or Primer-I22) should not be metallic when used on a protected surface that ismetal, especially aluminum, to avoid unwanted and possibly severegalvanic action corrosion from dissimilar metals being in contact. Otherclasses of fillers, pigments and substances that might modify otherphysical characteristics of the polymers may be added as well forcosmetic reasons. To be discussed later will be the group offriction-reducing fillers that may be used in the Polymer-O layer 3 todecrease friction between the protected surface moving rapidly relativeto the water.

FIG. 3 displays graphs of the concentration of the biostatic biocide[B.S] with depth into the antifouling coating from the water surface ofthe coating and which is labeled here on these graphs as 41 andsimilarly for the concentration of the biocidal biocide [B.C] which islabeled here on these graphs as 40. Polymer-O is again designated as 3and Polymer-I as 9 and are both labeled as such in FIG. 3(1) and FIG.3(6). The vertical axis of biocide concentration is labeled as 48 onFIG. 3(2) and the horizontal axis of depth of location within thebiofouling coating away from its water surface is labeled as 47 in FIG.3(2).

FIG. 3(1) shows the biostatic biocide in relatively high concentrationin Polymer-O 3, which diminishes quickly through the boundary region 42between Polymer-O 3 and Polymer-I 9 to the relatively low concentrationin Polymer-I 9. The concentration decreases over this natural boundaryarea due to diffusion of the biostatic biocide from a region ofrelatively high concentration to a region of low concentration.Similarly, the biocidal biocide in relatively low concentration inPolymer-O 3 increases quickly through the boundary region 42 to that ofthe relatively high concentration in Polymer-I 9.

The same situation holds for FIG. 3(2), only in this case Polymer-O 3was laid down on Polymer-I 9 while the former was still tacky and onlypartly cured, so that the two polymer layers were fused together as oneand the diffusion zone 42 for the biocides is significantly widened,because of the greater mobility of the biocide molecules.

FIG. 3(3) shows the biocide concentration gradients when a Primer-O 45is introduced between Polymer-O 3 and Polymer-I 9, with Primer-O 45bring impregnated with the biocides at the same concentration as isfound in Polymer-I 9, essentially making Primer-O 45 biocidal tobiofouling species in the same manner as is Polymer-I 9. The transitionzone is moved shallower into the coating and toward the water surface ofthe anti-fouling coating.

Similarly FIG. 3(4) shows the biocide concentration gradients when aPrimer-O 45 is introduced between Polymer-O 3 and Polymer-I 9 whenPrimer-O 45 is impregnated with the biocides at the same concentrationas is found in Polymer-O 3, essentially making Primer-O 45 biostatic tobiofouling species in the same manner as is Polymer-O 3. The transitionzone is moved deeper into the anti-fouling coating away from the watersurface.

FIG. 3(5) again shows the same situation as FIG. 3(3) and FIG. 3(4),except that this time Primer-O 45 has the same relatively high biostaticconcentration as that of Polymer-O 3 and the same relatively highbiocidal concentration as that of Polymer-I 9, which leads to two sharptransition zones, 41A and 41B, where at transition zone 41B therelatively high concentration of biostatic biocide in Polymer-O 3abruptly decreases to the relatively low concentration of biostaticbiocide in Polymer-I 9 and where, at transition zone 41A, the relativelylow concentration of biocidal biocide in Polymer-O 3 abruptly increasesto the relatively high concentration of biocidal biocide in Polymer-I 9.Abrupt transition zones can be widened if Polymer-O 3 is applied toPrimer-O 45 while Primer-O 45 is still tacky and not fully cured, andalso if Primer-O 45 is applied to Polymer-I 9 while Polymer-I 9 is stilltacky and not fully cured.

Finally, FIG. 3(6) shows the same situation as FIG. 3(5), only now theconcentration of the biostatic biocide in Primer-O is about 50% of thatof the relatively high concentration in Polymer-O 3 and the biocidalbiocide in Primer-I 9 is about 50% of the relatively high concentrationin Polymer-I 9. Again, the sharp transition zones, 41A and 41B, can bewidened through the mechanism just described for FIG. 3(5).

FIG. 4 shows a method of forming the biofouling coating describedherein. U designates the user of the coating at the time of use and Mdesignates the manufacturer manufacturing the coating. There are 3manners of use by which the biocides are added to the polymer layers,one by the manufacturer at the time of manufacture, and two by the userat the time of use. Component A is defined as the carrier polymer, withor without added fillers, pigments, and other particles, component B isdefined as the curing agent or hardener that effects a curing orhardening process on the carrier polymer, and component C is the biocidecomponent composed of the biostatic and biocidal biocides to be addedand the polymer carrier component A. Isopropyl alcohol, benzyl alcohol,methyl-ethyl-ketone (MEK) and other organic solvents may be added toeither component A or component C if the polymer carrier and biocidesare compatible with the solvent to help decrease the viscosity of thebiofouling coating so that the components A, B, and C can be mixedtogether more easily.

FIG. 4 also indicates that Polymer-O 3 and Polymer-I 9 may each beformed as per FIG. 4, only the formation of Polymer-I 9 is described indetail. The same procedure would be done for Polymer-O 3. Component C isa mixture or solution of biocidal polymer and biostatic polymercomprising about 0.1%-about 50% by weight of component C, and about 50%to about 99.9% by weight of component C would be the carrier polymer(component A) itself.

Process 1 calls for the addition by the manufacturer of ComponentC_(inner polymer) to be added to Component A_(inner polymer) at the timeof manufacturer to produce a mixture, (A_(I)+C_(I)), that is shipped bythe manufacturer, M, to user U along with hardener Component B innerpolymer. At the time of use, user U mixes hardener ComponentB_(inner polymer) together with mixture (A_(I)+C_(I)) to give the finalinner polymer biocidal coating, Polymer-I 9, whose components aredesignated as mixture (A_(I)+B_(I)+C_(I)). This coating is then appliedto the surface to be protected (or to the inner polymer primer,Primer-I, if used) to form the inner biocidal coating, Polymer-I.Likewise, the same procedure is followed for the outer biostatic polymercoating, Polymer-O. Though not shown in FIG. 4, the formation processmay be exactly the same, where the manufacturer M adds biocide ComponentC_(outer polymer) at the time of manufacture to the carrier polymerComponent A, A_(outer polymer), to produce a mixture, (A_(O)+C_(O)),which is then shipped to user U along with hardener ComponentB_(outer polymer). At the time of use, user U mixes hardener componentB_(outer polymer) with the mixture (A_(O)+C_(O)) to give the final outerpolymer biocidal coating, Polymer-O, whose components are designated asmixture (A_(O)+B_(O)+C=). This coating is then applied to the innerbiocidal layer, Polymer-I (or an outer polymer primer if used) to givethe outer biostatic polymer coating, Polymer-O. The same process wouldbe applied to Primer-I and Primer-O if used and if both containbiocides. If they are used but they do not contain biocides, there wouldbe no C component for the primers, and Component A (polymer primercarrier) and Component B would be sent to user U by manufacturer M as iscustomary for use by user U at the time of application. Because theformation process is identical for polymer primers containing biocides,a detailed description of the formation process for these coatings willbe omitted.

Continuing to refer to FIG. 4, process number 2 for the reconstitutionof the biofouling coating is shown for the Polymer-I layer, with asimilar procedure for Polymer-O, Primer-I, and Primer-O, if the primersare used and contain biocides. Manufacturer M does not add biocideComponent C_(inner primer) at the time of manufacture as in processnumber 1. Instead, the manufacturer M sends to user U three separatecomponents, the carrier primer, A_(inner primer), the hardening agentfor the carrier polymer, B_(inner polymer), and the biocide containingComponent C_(inner polymer), who will reconstitute the polymer coatingat the time of use.

At the time of use, user U mixes polymer carrier ComponentA_(inner polymer) with the biocide containing ComponentC_(inner polymer) producing mixture (A_(I)+C_(I)), to which hardening orcuring agent Component B inner polymer is added to produce the finalmixture (A_(i)+B_(i)+C_(i)) which is Polymer-I as in process 1. Asimilar process would be used for Polymer-O, and if they are used andcontain biocides, Primer-I and Primer-O.

Process number 3 for the reconstitution of the biofouling coating isagain shown for the Polymer-I coating. Manufacturer M again does not addthe biocide component C_(inner primer) at the time of manufacture.Instead, again Manufacturer M sends to user U all three components ofthe biofouling coating, carrier polymer Component A_(inner polymer),hardening agent component B_(inner polymer), and biocide containingcomponent C_(inner polymer). At the time of use, user U mixes hardeningagent Component B_(inner polymer) with Component A_(inner polymer) tomake mixture (A_(i)+B_(i)), and to this mixture, biocide containingcomponent C_(inner polymer) is added just prior to application to aprotected surface, again yielding mixture (A_(i)+B_(i)+C_(i)), which isnow used to coat the protected surface. A similar such process 3 wouldbe used for Polymer-O, and if they are used and contain biocides,Primer-I and Primer-O.

At no time is the hardening agent Component B in concentrated form everin contact with the biocide containing Component C, a situation whichotherwise might cause the biocides in component C to come into contactwith the highly reactive Component B hardener, as this can possibleimpact unfavorably affect the final curing, mechanical, chemical, oroptical qualities of the polymer layer or might affect the biocidesthemselves, thus changing their biocidal characteristics. The only timeComponent C comes into direct contact with Component B is when inProcess number 3, after Component B is mixed with Component A at thetime of use. When Component C is next added to the mixture of ComponentA and Component B, Component C is only exposed to a very diluteconcentration of hardener Component B, which has been heavily dilutedwith careful mixing with Component A. Careful and extensive mixing isused to prevent any chance of component C from coming into contact withconcentrated component B. Any fillers to be used with any of the polymerlayers used in the biofouling coating would be added to the polymercarrier at the time of manufacture, although the fillers could be sentseparately and added to the mixture by the user U at the time of use.

Each polymer layer—Polymer-O, Polymer-I, and if used, Primer-O andPrimer-I, would have its own kit and such separate kits would be shippedto the User U by manufacturer M. Each biocide Component C for eachpolymer layer in the final multi-layer biofouling coating would beuniquely different and matched to that particular desired polymer layer.Manufacturer M would either formulate its own biocide containingComponent C for use with a particular polymer coating (Component A) andits hardening (or curing) agent (Component B) and the three ComponentsA, B, and C would be sent out to the user U, unless components A, and Care pre-mixed together at the time of manufacture (Process number 1,where component B and mixture (A_(i)+B_(i)) would be sent out to userU). Manufacturer M can also arrange to have pre-mixed Component C kitsmanufactured by a third party who would ship it to Manufacturer M forinclusion into its polymer coating kits.

The biocide-containing Component C used with a specific polymer for aspecific application would be unique for that specific polymer and itshardener to guarantee that the biocides and the hardener would notchemically interfere with each other and that the biocides used wereconsistent with the application being involved in preventing biofoulingby invertebrate calcium forming organisms as well as the carrier polymerbeing consistent with the needs of the application under consideration.

The inclusion of a suitable algaecide can be formulated in Component Cas well and added to the invertebrate biocides to give the outsidebiostatic polymer layer, Polymer-O, algaecide capabilities as well. Suchchemical compounds can be chosen from the table of herbicides listed inFIG. 21C and may be added to Component C in the same manner of and inthe same percentages of weight composition of that of the invertebratebiocides.

FIGS. 5A and 5B demonstrate the polypharmaceutical process of biofoulingorganism cell kill. In FIG. 5A, a cut-away view of the biofoulingcoating is shown including a biostatic biocide 51 in relatively highconcentration and a biocidal biocide 52 in relatively low concentrationmaking up Polymer-O 3 and a biocidal biocide 52 in relatively highconcentration and a biostatic biocide 51 in relatively low concentrationimpregnating Polymer-I 9. Barnacle cyprid larval forms 50 from aquaticenvironment 2 (labeled in FIG. 3B) are shown having attached themselvesto the water surface 1. The cut-away view on the left, FIG. 5A(1)illustrates barnacle cyprids trying to attach themselves to the watersurface 1. Because of the presence of a relatively high concentration ofbiostatic biocide 51, such as capsaicin, helped by a relatively lowconcentration of biocidal biocide 52, the vast majority (in thisexample, all but two) are shown as having detached themselves from thatsurface in FIG. 5A(2). Detached cyprids are designated as 55 and theywill swim off to either try to find a more hospitable surface to settleon or, more likely, they will eventually die.

However, in this example, two cyprids 50 are apparently resistant forwhatever reason to the biostatic biocide and remain attached to thewater surface 1 of the coating. They continue to grow and mature intojuvenile barnacles, with this process taking about 6 to about 24 hours.The cyprids 50 will then begin to burrow into Polymer-O of the coating,potentially causing damage to the surface 53 being protected.

However, because of the presence of the relatively high concentration ofbiocidal biocide 52, such as ivermectin, helped by the presence of a lowconcentration of biostatic capsaicin, the two biocides will togetherkill the juvenile barnacle, now about 0.1 mm in diameter, before it willever reach the surface 53.

However, FIG. 5B demonstrates an even more effective way of producing anincreased organism kill. The same structural coating is shown as in FIG.5A, but the composition has changed so that there are now two biostaticbiocides, both of which are in relatively high concentrations. In thisexample, the first biostatic biocide 51 (e.g., capsaicin) is used, pluseither a low dose second biostatic biocide 58 (e.g., pyrethrin orpyrethroid-type of insecticide or cupro-nickel powder) in relativelyhigh concentration. The relatively high concentration of the secondbiostatic biocide replaces the need for a relatively low concentrationof the biocidal biocide. Because of the marked synergistic effect ofthese two potent biofouling inhibitors, now no barnacle cyprids 50remain attached and all barnacles now are free floating (labeled 55).Polymer-O 3 is now totally free of barnacles as shown in FIG. 5B(2).

This result is due to parallel action of the two biostatic biocides.Also, Polymer-I may be impregnated with a second biocidal biocide. Forexample, in addition to the ivermectin, one can use Lufenuron or highconcentrations of a pyrethrin or pyrethroid type of biocide togetherwith piperonyl butoxide, which prevents metabolism of the pyrethrincompound. Together, with the Lufenuron acting as a chitin synthetaseenzyme inhibitor, or a high level pyrethrin impregnation inhibiting thebarnacles GABA receptor acting in conjunction with the ivermectinhyperpolarization of the cyprid's nervous system, a synergistic effectis produced.

It is important to note that these chosen biocides are not impregnatedinto the polymer layers as a random composition. Rather, combinations ofcellular metabolic and physiological processes are selected that can beinterfered with or blocked, producing the most effective biostatic orbiocidal effect. The present embodiments thereby achieves “synergistic”inhibition and lethality, where the biocide combination's inhibitoryeffects, killing effects, or both exceed the effects of each separatedrug alone, and “synthetic” inhibition and lethality, when a firstcellular mechanism is blocked by a first biocide, but a second cellularmechanism is available to bypass the blocked first cellular mechanism.However the organism is nonetheless inhibited or killed effectivelybecause of the presence of a second biocide, which blocks the secondcellular mechanism.

Referring to FIG. 6A, a cut-away view of an embodiment of theanti-fouling coating is shown, enhanced to provide control of algaeinfestations on submerged surfaces in addition to controlling ofinvertebrate calcium-forming infestations. FIG. 6A(1) shows the basictwo-polymer layer of the biofouling coating as shown previously. Notethat or the biofouling coating in FIG. 6A(1) is effective against animalbiofouling organisms and not effective against plant biofoulingorganisms. Thus organisms bryozoans 61, invasive mussels 62, shipworms(marine woodborers) 63, and barnacles 65 are shown detached from thewater surface of the coating 1 and are floating in aquatic environment2. They are successfully repelled by the biostatic effect of Polymer-O3. The organisms further include algae 60, fungi 66, and biofilm 64adherent to the water surface 1, providing a means for the larval formsof invertebrate animals to settle on the surface without actuallytouching it initially. This is not desirable because the biofilm shieldsthe larval form from the Polymer-O layer 3 as well as causes undesirablecosmetic effects.

By adding an algaecide 70 to Polymer-O 3 of FIG. 6A(2), especially abroadly phytotoxic algaecide with activity against all three categoriesof plants, algae, fungi, and bacteria, all the organisms, both plant andanimal, are no longer attached, and the biofilm has disintegrated. Oneexemplary algaecide that may be used is a metal pyrithione salt such aszinc pyrithione, but any metal salt of pyrithione or mixture of suchmetal salts will do, including for example copper, barium, silver,strontium and so forth. Pyrithione compounds have broad spectrumphytotoxicity against all three categories of plants and an exceptionalsafety profile for animals and humans. Furthermore, any low watersolubility herbicide listed the table of FIG. 21C will be appropriatefor use as an algaecide as well.

Referring to FIG. 6B(2), a cut-away view is shown of an embodiment ofthe anti-fouling coating of FIG. 6B(1), enhanced by the use of not onlythe algaecide 70, but also a second biostatic biocide 73 in Polymer-Oand a second biocidal biocide 71 in Polymer-I. As a result of theenhancements of the addition of algaecide 70 and the additionalbiostatic biocide 73 in Polymer-O 3, all organisms, including plantorganisms, are inhibited from attaching. The chance of any invertebratebiofouling organism being resistant to the Polymer-O layer 3, and thetwo biostatic biocides that are now in the Polymer-O layer 3, is muchreduced. If there is a particularly hardy organism that can attach inspite of such a broad spectrum of biostatic coverage, and it attempts topierce and grow through Polymer-O 3 and grow through the boundarybetween Polymer-O 3 and Polymer-I 9, it will be killed by the morepotent biocidal nature of Polymer-I 9 enhanced with an additionalbiocidal biocide 71 while it is still a microscopic juvenile form. Thepits on Polymer-I's boundary left by the dead invertebrate animal willbe so tiny that the leakage of the more potent biocides of the Polymer-I9 layer will be essentially non-existent, with that latter layer stillbeing completely shielded from the aquatic environment 2 by Polymer-O 3.

FIG. 7 depicts a series of 6 sequential cut-away views of theantifouling coating that illustrate the sequential toxicity that thepresent embodiments deliver to diverse biofouling organisms. Againpresent are biostatic biocide 5 and biocidal biocide 4. FIG. 7(1)depicts anti-fouling coating comprised of Polymer-O 3 and Polymer-I 9(labelled in FIG. 7(4)) being attacked simultaneously by mussel larvae(veligers) 82A and barnacle larvae (cyprids) 81A swimming freely inaquatic environment 2 looking to attach to water surface 1 of theanti-fouling coating protected submerged surface 19. This example is forillustration only, as in practice fresh water invasive mussels, quagga,and zebra mussels would not be in the same body of water as saltwaterinvasive barnacles. Initial attachment of multiple cyprids 81B andmultiple veligers 82B are shown in FIG. 7(2). FIG. 7(3) shows that mostof the veligers 81C and cyprids 82C are repelled and float away into theaquatic environment as a result of the biostatic effects of contact withPolymer-O 3.

However, one veliger 81B and one cyprid 82B are resistant to thebiostatic nature of Polymer-O 3. Over a 6 to 24 hour period afterimplantation, cyprids and veligers start and complete theirmetamorphosis and maturation to a juvenile form and they grow slightlylarger, changing form as represented by 81D juvenile mussel and by 82Djuvenile barnacle in FIG. 7(4). In FIG. 7(5) further growth of juvenilemussel 81E and juvenile barnacle 82E is shown, now piercing Polymer-O 3completely and piercing the boundary between Polymer-O 3 and Polymer-I9.

As soon as juvenile mussel 81E and juvenile barnacle 82E come in contactwith Polymer-I 9 and its relatively high concentration of biocidalbiocide 4, enhanced by its relatively low concentration of biostaticbiocide 5, they are killed and float away dead as a dead juvenile mussel81F and a dead juvenile barnacle 82F. At the time that Polymer-I 9 killsthese juvenile forms, they are only 0.1 mm (100 microns), so they areessentially still microscopic. As a result the microscopic ringeddefects left by their sharp-ringed immature cells leave tiny circularmicroscopic pits on the water-surface of Polymer-O 3. These pits are ofno consequence because of their small size and the fact that they are sosmall in number.

Furthermore, tiny circular microscopic pits are left for the same reasonon the surface of Polymer-I 9, but do not extend through the thicknessof Polymer-I 9. This has two important consequences. First, Polymer-I 9is never pierced to allow damage to be done to protected surface 19.Second, the surface defects are so small that there is no significantleakage or chemical leaching out of Polymer-I 9 into the surroundingwater 2. Because Polymer-O 3 is still intact, resulting from the numberof the defects in that polymer layer being so small and few in number,Polymer-O 3 continues to provide complete shielding from exposure to theaquatic environment to Polymer-I 9. That is the reason why even such atoxic biocidal agent like TBT can be used safely.

FIG. 8 shows an embodiment of the antifouling coating with a widespectrum of activity. Depicting a cut-away view of the coating,Polymer-O 3 and Polymer-I 9 are present. In this example, Polymer-O 3contains, e.g., biostatic biocide cupro-nickel (CN) 89 and biostaticbiocide low-dose pyrethrin compound (Py) 90, and Polymer-I 9 contains,e.g., biocidal biocide high dose pyrethrin compound 81 with piperonylbutoxide (x) 84, which is not itself a biocide but which enhances thelethality of high dose pyrethrins and pyrethroids, and biocidal biocide,Lufenuron (LU) 82. All of these biocides have activity againstinvertebrate calcium-forming biofoulers using different mechanisms ofaction as previously described.

In addition, Polymer-O 3 contains the algaecide, pyrithione as ametallic salt (PN) 94 to control algae, fungus, and bacterialproliferation as biofilm and bioslime. The aquatic environment 2, thewater surface 1 of the antifouling coating, the surface 19 beingprotected, the interior 86 of the surface 19 being protected, and theboundary 87 between Polymer-O 3 and Polymer-I 9, are also shown.

The mechanism of actions of these biocides include:pyrithione—disrupting cellular membrane transport blockage of the protonpump that energizes cellular transport mechanisms which, in turn,results from a pyrithione-induced increased uptake from the environmentof copper increasing, intracellular copper to toxic levels; pyrethrinsand pyrethroids—GABAa receptor modulator and inhibitor; lufenuron—chitinsynthetase enzyme inhibitor; cupro-nickel—GABAa receptor modulator andinhibitor, piperonyl butoxide—CYP 450 cytochrome inhibitor preventingmetabolism of the pyrethrin compound.

Sequentially, the plant invasive species encounter a pyrithione metalsalt (PN) 94 in Polymer-O which inhibits biofilm formation and algaefrom attaching, while the animal invasive species encounter both thebiostatic biocides of a low dose pyrethrin compound (without piperonylbutoxide) (PY) 90 and cupro-nickel powder in low concentration (CN) 89,which synergistically will inhibit attachment of larval forms to thewater surface 1 of the antifouling coating, preventing the invertebratelarvae from attaching. Then, if any invertebrate species make it throughthe Polymer-O layer 3 (algae will never penetrate it unless the way isled by a calcareous invasive organism), they will be destroyed by thesynergistic lethality effect of combined high dose pyrethrin compound(PY) 83 together with the piperonyl butoxide (x) 84 and lufenuron (LU)82.

There would be very little chance of significant numbers of invasiveinvertebrate biofouling organisms making it through both Polymer-O 3 andPolymer-I 9 layers to cause any bio-corrosive damage to the surfacebeing protected 19. There would also be very little chance that the twobiocide impregnated Polymer-I layer 9 would suffer any significantdamage. Finally, there would be very little chance that Polymer-I 9would be compromised sufficiently to allow any of the more potentbiocidal biocides to leach into the aquatic environment 2.

FIG. 9 depicts a series of three cut-away side views showing theinhibition of attachment and subsequent progressive penetration of thebiofouling coating and the effects of such penetration on the integrityof the coating. Referring to FIG. 9(1), which depicts the penetration bya young barnacle of a coating, such as ordinary marine paint, and itsunderlying surface when the biofouling coating of this invention is notin place and the coating has no other invasive biofouling controlmechanism in place. A similar situation occurs with a developing younginvasive mussel attacks the same type of coating. A generic protectivecoating 93 is shown that does not inhibit invasive species invasion byany other type of antifouling compound in the coating. The aquaticsurface 91 of a biofilm or bioslime deposit on coating 93 and theinterior 92 of that biofilm are also shown.

A barnacle cyprid 87A is shown having just settled down and attacheditself to the biofilm (87B) and continues to grow and penetrate thebiofilm (87C), finally invading the coating 93. By this time (6 to 24hours after the initial settlement and attachment), the cyprid haschanged to juvenile barnacle (87C). The juvenile form now invadescoating 93, going through and attaching itself to the underlyingprotected substrate 19 by a structure known as a byssel thread 89 thatalso has extremely tough and very adhesive glue. This tough and veryadhesive glue can induce corrosion in metals.

Next, the juvenile barnacle 88E penetrates deeper, developing anextremely sharp and ringed shell 90 that allows penetration through thecoating 93, and begins to destroy the protected surface itself. Fromthat point the organism's invasion is complete and the barnacle will befirmly implanted irrevocably within the coating. Bio-corrosion will setin, destroying or at least interfering with the function of theprotected surface. At this point, the barnacle will stop growing in, andinstead grow outward and in diameter, with the surface defect rangingfrom about ¼″ in diameter to as much as 3″ in diameter, depending uponthe barnacle species. A similar such growth diagram could be constructedwith veliger larvae belonging to invasive mussels.

FIG. 9(2) shows the growth process for a barnacle when a biofoulingcoating according to one of the present embodiments. Surface 19 thistime is covered by a bilaminar coating that includes biocidal innerpolymer layer Polymer-I 9 that covers surface 19. In turn, biostaticouter polymer layer Polymer-O 3 covers Polymer-I 9 and shields thatinner polymer layer from any contact with the aquatic environment 2. Nowcyprid 87A alights on biofilm surface 91 from aquatic environment 2. Itevolves into cyprid 87B, penetrating the surface 91 of the biofilm intothe interior 92 of the biofilm. Further growth as a transforming cypridinto a juvenile form 87C begins to proceed and now the cyprid piercesthe biofilm and invades the biostatic Polymer-O layer with its earlydeveloping shell 90. At this point, contact with the biocides inPolymer-O 3 activates its vanillin receptors secondary to the capsaicinand its GABAa receptors are inhibited by a pyrethrin compound if theseare the two biocides used. The cyprid (87D) pulls away from the watersurface 1 (Labeled in FIG. 8) of Polymer-O 3 and floats away to eitherattach at some other location or else die. Virtually no damage results,even on a microscopic scale, and Polymer-O 3 remains completely intact.Polymer-I 9 just underneath sustains no damage.

FIG. 9(3) shows the growth process for a barnacle on the rare occasionwhen a barnacle cyprid manages to attach and continues to develop into ajuvenile form. As before, cyprid 87A attaches to the surface 91 of thebiofilm, progresses into cyprid 87B growing now in the interior 92 ofthe biofilm, becoming deeply embedded into the biofilm as cyprid 87C,and finally penetrating the biofilm layer as cyprid 87D and growing intobiostatic Polymer-O 3 with a developing sharp ring shell 90 and bysselattachment thread 89. In this example, the cyprid 87D resists thebiostatic biocidal effect of the Polymer-O layer 3, growing intojuvenile barnacle form 87E which pierces through the entire thickness ofPolymer-O 3. Its sharp shell reaches through the boundary of Polymer-O 3and Polymer-I 9 to invade the biocidal Polymer-I 9 with its shell.

As soon as the juvenile cyprid 87E reaches the Polymer-I layer, however,it encounters the lethal biocidal biocide or biocides and it is killed.The dead juvenile form 87G, still only about 0.1 mm in diameter (100microns), releases its grip from the antifouling coating and floatsaway. A small defect 94 of about 0.1 mm in diameter remains in thebiofilm 92 and Polymer-O 3, and an even smaller ringed defect 93 ispresent in the top surface of Polymer-I 9. The defect in the biofilm isquickly covered, the ringed defect 94 in Polymer-O is too small and toorare to be of any consequence, and the even smaller defect 93 inPolymer-I is also of no consequence. The more potent biocidal biocide orbiocides in the Polymer-I layer 9 are still shielded from the aquaticenvironment 2. The surface to be protected remains completely unharmed.

FIG. 10A depicts cut-away views of 4 additional structural embodimentsof the current invention. Referring to FIG. 10A, both Polymer-O layer 3and Polymer-I layer 9 can be made either biostatic or biocidal, such asin FIG. 10A(3) or the biocidal inner Polymer-I layer 9 can actually makeuse of a relatively toxic biocidal biocide like a copper or zinc saltsuch as in FIG. 10A(1) or a very toxic type of biocidal biocides such asTBT such as in FIG. 10A(2), because of the shielding effect of the outerPolymer-O 3 layer keeping the toxic biocide away from the aquaticenvironment so that it does not chemically leach out. FIG. 10A(4) is yetanother variation where the Polymer-I uses two biocides, biocidecupro-nickel used in high concentrations along with another biocidalbiocide, ivermectin, and the outer polymer-O layer 3 uses two biocidalagents, capsaicin, and low dose pyrethrin, as well at that layer havingalgaecide properties with the addition of a metal pyrithione salt.

FIG. 10A(1) shows an antifouling coating where the Polymer-O layer 3contains the biostatic biocide, capsaicin (CA) 100 and a metalpyrithione (MP) 101, which provides invertebrate biostatic and algaecideproperties to the outer polymer coating of the anti-fouling coating.Polymer-I is impregnated with the biocidal biocide, a high concentrationpyrethrin or pyrethroid compound (PY) 104 together with piperonylbutoxide (PB) 107 and a biocidal metal or metal salt (M) 103 that can becopper, cuprous oxide, copper thiocyanate, zinc, zinc oxide, or zincthiocyanate, and other metal compounds often used in metal based bottomboat paints. The result is an enhanced anti-fouling bi-laminar polymerpaint coating that provides the benefits of copper based bottom paints,but with these benefits enhanced with synergistic lethality from thepyrethrin compound against invertebrate biofouling organisms, and anability to prevent attachment of these organisms in the first place, aswell as plant invasive species, accomplishing all of this withoutundesirable copper and zinc ions in the form of copper and zincoxychloride chemically leaching into the aquatic environment. Thekilling of the invertebrates is done at the surface of the Polymer-Ilayer rather than being done in the water adjacent to the anti-foulingcoating such as in the case of a copper-based paint.

A further demonstration of how effective this bi-laminar polymerstructure can be in reducing the hazard potential of biocidal biocidesused in the antifouling coating to the aquatic environment is depictedin FIG. 10A(2). Here an embodiment is shown which has an outer Polymer-Opolymer layer 3 that includes the biostatic biocide, capsaicin (CA) 100,and the biostatic low-concentration pyrethrin (PY) 104 compound toproduce the invertebrate biofouling attachment inhibition. However, theinner Polymer-I polymer layer contains only one biocidal biocide, theexceedingly potent, but banned TBT (tributyltin) (TBT) organo-tincompound 105 that is biocidal to all common and important biofoulingorganisms, plant or animal.

Normally, TBT is too toxic to the environment and thus cannot be used.However, with the bi-laminar polymer structure of the current invention,the TBT is contained completely within the Polymer-I layer 9, totallyshielded from the aquatic environment by the outer Polymer-O layer 3.The maximal exposure of TBT to the aquatic environment would have amicroscopic defect left by an occasional invertebrate biofoulingorganism that would manage to penetrate the Polymer-O layer and then bekilled on contact with the TBT containing Polymer-I layer. Thus insteadof an entire ship's hull leaching TBT continuously over time into thewater just adjacent to the surface, the organism is killed only oncontact with the TBT at the surface of the Polymer-I 9 and the maximumsize of the surface exposed to the water would be a circle estimated tobe about 0.1 mm in diameter (100 microns) or 0.0075 sq. mm, an amount ofsurface area that is so small that there is essentially no leakage ofTBT into the aquatic environment. Furthermore, whatevermicro-quantitative leaching would occur, it would occur in the first oneor two weeks following the breach and killing of the organism and theTBT in that tiny area of exposure would stop leaching because ofdepletion of the TBT around the ringed pit left by the invertebrateshell after it fell off and died. Thus the current embodiments wouldallow even a very toxic biocide like TBT to be used safely. Note that ametal pyrithione salt (MP) 101 may also be added to the Polymer-O layerfor algaecide properties. TBT is a potent algaecide, but since it mustbe kept from contact with the aquatic environment by containment withinthe Polymer-I layer 9 and shielded from the water by the Polymer-O layer3, it cannot exert its algaecide properties as it won't be in contactwith invading algae.

The ability of the outer Polymer-O outer layer to shield the aquaticenvironment from a more toxic biocide present in the Polymer-I innerlayer extends out further than with the use of TBT, zinc and coppermetals and metal salts, and it extends out further than with all of thebiocides mentioned above, including, e.g., Anti-helminthic compoundssuch as Ivermectin, Avermectin, Fenbendazole, Albendazole; Pyrethrinsand synthetic Pyrethrinoids; halogenated biocides including Lufenuron;spinosyns; Chinese folk law medicinal agents including Thunder Godextract; biocidal synthetic biologically active agents that are ratedhigh, very high, and extremely high levels of toxicity to the aquaticenvironment as listed in tables FIGS. 21A, B, and C; and natural plantalkaloid families possessing biostatic and biocidal insecticidalproperties including representative examples such as terpenoids, thundergod vine, and chrysanthemum pyrethrins, as well as any other member ofthe group of natural plant alkaloid families as mentioned in FIG. 21D.

The outer Polymer-O layer will protect against virtually every biocideused in anti-fouling applications that can be used to impregnate a paintcoating polymer layer in the marine coating industry, which universallyhave aquatic toxicity. These environmentally toxic substances caninclude products widely used in the shipping industry, some of which arein the process of being banned by certain jurisdictions. These biocidesinclude halogenated organic biocides such as: Sea-Nine® Dupont(4,5-dichloro-2-octyl-3-isothiazolone), cybutryne (Ingarol®), simazine,tralopyril, and Econea® (chlorfenapyr). Furthermore, even antifoulingbiocides that would leach rapidly into the aquatic environment becauseof a high water solubility rate, associated with a low molecular weightand low Koc, or an intrinsic high aquatic toxicity, can now be used asthe inner Polymer-I layer, without a risk of either environmentaltoxicity or a premature cessation of anti-fouling properties. As aresult, all of the biologically active agents listed in FIGS. 21A, B, C,and D are acceptable biocidal agents in coatings on water submergedsurfaces.

FIG. 10A(3) shows an embodiment of the present invention where thebiofouling coating is composed of a Polymer-O layer 3 and a Polymer-Ilayer 9 that are both biostatic. While this embodiment might not be aspotent as the prior embodiments discussed previously to this point,there are applications where simple inhibition of attachment ofinvertebrate biofouling organisms might be all that is required. Theseapplications include protecting surfaces that are flexible, such asropes, cables, and fishnets.

In FIG. 10A(3), a Polymer-O is shown that includes two biocides, a firstbiostatic biocide (e.g., cupro-nickel powder (CN) 106, in a 90%/10% byweight composition of copper to nickel with cupro-zinc or cupro-silveralloys, and brass powders being suitable substitutes in a composition byweight of 0.01% to 50%, but with a preferred composition by weight of0.1% to 10%, with a particle size of a range of sub-micron to 100microns) and a second biostatic biocide (e.g., capsaicin (CA) 100). APolymer-I 9 may have a high relative concentration of cupro-nickelpowder and a low relative concentration of capsaicin powder. Note thatat lower concentrations by weight, cupro-nickel tends to be biostatic,and at higher concentrations, biocidal.

Of particular interest is the cupro-nickel powder, where the inherentsolid solution alloy of this alloy and similar alloys, such ascupro-zinc and cupro-silver, has physical and chemical properties thatresult in no significant leaching of metal ions into the water, as thesurface of such alloys are protected by a passivated layer. The onlyproviso is that these alloys should not be used in water with hydrogensulfide being present (e.g., brackish swamp water with high bacterialcounts of sulfide producing bacteria, such as where sewage is likely tobe present or in a swamp), as these alloys would display undesirablecorrosion into sulfides. Note that in this embodiment, in the Polymer-Olayer 3 there is a high relative concentration of the capsaicin 104biostatic biocide and a low relative concentration of the cupro-nickel106 biostatic biocide. In the Polymer-I layer 9 the relationship isreversed, with a high relative concentration of the cupro-nickel biocidewhich, at these higher concentrations, is more biocidal and lessbiostatic but still nevertheless biostatic overall in nature, and a lowrelative concentration of the capsaicin.

Thus both the Polymer-O 3 and the Polymer-I 9 are biostatic. If anorganism manages to resist the biostatic combination in the Polymer-Olayer and attach itself there, it will be likely to be repelled by thereversal of the biostatic composition in the Polymer-I layer anddisengage itself from the surface as soon as it contacts the innerbiostatic layer. In this embodiment, the organism will most likely notbe killed on contact with the Polymer-I layer but will likely die laterafter it detaches. Note that the capsaicin, as in all of the structuralembodiments of the current inventions, is used either in the form ofcrystals, of 99% or better purity, or in the form of purified extract ofgreater than 95% purity at a percentage by weight ranging from 0.01% to50%, with a preferred percentage by weight with a preferred range of0.1% to 10%. In the case of the cupro-nickel, the same percentagesmentioned above apply to the inner Polymer-I layer as well. Although theratio of the concentration of the cupro-nickel powder in the outerPolymer-O layer as compared to the inner Polymer-I layer would be apreferred 1:10 ratio, that ratio could vary from 1:1 to as high as1:1000.

In FIG. 10A(4) we have a structural embodiment of the current inventionwhere the Polymer-O outer layer 3 is impregnated with biostatic biocidecapsaicin (CA) 100, biostatic biocide low concentration of a pyrethrinor pyrethroid (PY) 108, and a metal pyrithione salt (MP) 101. Polymer-Iinner layer 9 is impregnated with biostatic biocide Cupro-nickel powder(CN) 106, but in higher concentration, and biocidal biocide ivermectin(IV) 107. This combination of biocides results in a predominantlybiostatic outer polymer layer with algaecide properties as well, and apredominantly biocidal inner polymer layer. The number of differentvariations and permutations possible to be suitable for variousbiofouling applications is extremely large and it would not be possibleto go over each and every configuration possible that can comprise thisinvention. The examples provided herein are therefore solelyillustrative and should not be considered limiting.

Medetomidine is a biostatic biocide with the unusual property thatalthough it is relatively of higher water solubility of 186 mg/L,greater than the 100 mg/L limit previously specified, it nevertheless,is extremely tightly fixed within the polymer matrix it impregnates. Asa result, in situations where shorter multiyear period of effectivenessis tolerable, such as coatings on cables, lobster traps, and ropes, itsleaching rate will be low enough to allow its use in the outer biostaticPolymer-O layer. Its larvae repelling activity is based on thestimulation of the biofouling larvae nervous system via octopaminereceptors causing convulsions of its muscular structures forcing theorganism to pull away from the protected surface. It is effective inconcentrations from 0.1% and higher though the preferred range wouldextend from 0.1% to 10%.

All the biocides that have been specified so far, and all thesubstitutions for such biocides, that are specified to be present in thePolymer-I and Polymer-O layers are comprising by weight about 0.01% toabout 50% of the total weight of the compositions of the Polymer-I andPolymer-O layers, with a preferred range of about 0.1% to about 10% forbiostatic biocides in the Polymer-O layer and about 0.1% to about 5% forbiocidal biocides in the Polymer-I layer. These preferred ranges areknown not to affect the mechanical, curing, or chemical properties ofany of the polymers and provide, under usual circumstances of typicalbiofouling infestations, sufficient potency. Higher concentrations maybe used for severe infestations, subject to limitation in some cases bythe physical properties of certain polymers and/or their curing agents.

The preferred range, however, may vary for specific biocides used withspecific polymers. The substituted biocides may be drawn from the listsof pesticides listed in the tables of FIG. 21, as well as the classes ofcompounds listed in the definition of terms section above. The maximumsummed concentrations of all biocides in any layer of the antifoulingcoating should be a maximum of about 50% to avoid deleterious effects onthe physical, chemical, and curing properties of the polymer layer thatthey impregnate, with a preferential range of about 0.01% to about 20%.Furthermore, the maximum summed concentration of all the biocides andfillers used in a given polymer layer of the antifouling coating shouldbe about 50% at a maximum. It is noted, however, that some epoxy resinprimers of the zinc-enriched type, which can serve in some applicationsas the Polymer-I layer, can have up to 90% by weight of zinc powderfiller, indicating that certain polymers have physical and chemicalcharacteristics that will allow the weight percentage on filleradditives to exceed 50%.

Fillers that might be added to Polymer-O and Polymer-I include pigments,abrasives and hardness-enhancing particles. These fillers can alsofavorably impact adhesion and can include carbon fiber, aramid silica,fluorspar, stainless steel and other metals, boron carbide, othercarbides, cubic boron nitride, industrial diamond powder, andfriction-reducing fillers such as silicone powder, PFTE powder,molybdenum disulfide powder, non-cubic boron nitride, graphite flakes,graphene nanoplatelets, oxide, and flouride and may be present in arange of about 0.01% to about 50% by weight of the Polymer-O, Polymer-I,Primer-O, and Primer-I layers, with a preferential range of 1% to 15%.The size of such filler particles may range from sub-micron in size to100 microns, with a preferential range being about 20 to about 50microns for the abrasive fillers, and less than about 1 micron to about20 microns for the friction-reducing fillers.

One non-organic biocide that is of beneficial use in this invention,cupro-nickel powder, may also be considered to be a filler material.However, because it is also a biocide, and smaller sized particles for agiven mass of biocide have a greater relative surface area, allowinggreater contact with the biofouling organism, the preferred particlesize would be as small as possible, e.g., <20 microns, and preferably,<1 micron.

The sum total of all the biocide and non-biocide additives to thepolymer layers is preferentially about 50% or less to minimize thepossible effects on the curing, hardening, chemical, and mechanicalproperties of the polymer. Thus the percentages of some additives wouldput limits on the percentages of the other additives to ensure that thestructural, mechanical, hardening, and chemical properties of thepolymer to which they are added, which will form the polymer layers ofthis invention, would not be undesirably altered in a manner to degradefrom its performance and structural and chemical integrity. Thepercentages of these components can be modified for specificapplications. All such additional modifications and compositions thatemploy the structural aspects of this invention would be considered tobe additional variations on the embodiments described in this disclosurefor the current invention.

While all the structural embodiments so far have depicted the outerPolymer-O polymer layer as being biostatic in nature, because of thehigh relative concentration of the biostatic biocide as compared to therelative low relative concentration of the biocidal biocide in thatPolymer-O layer, and have depicted the inner Polymer-I polymer layer asbeing biocidal in nature because of the high relative concentration ofthe biocidal biocide as compared to the relative low concentration ofthe biostatic biocide in that Polymer-I, there are several additionalspecialized embodiments that are depicted in FIG. 10B that can be usefulin certain anti-fouling applications requiring exceptionally long lifeif exceptionally durable fluoropolymers are used together with morepotent biocide arrangements.

In these embodiments, the polymer in both layers may be either aflourourethane, a flouro-ethylene-vinyl-ether (FEVE), or a related,extremely durable fluoropolymer. It is specified that the Polymer-Olayer is applied onto the Polymer-I layer while the latter is onlypartly cured and still tacky, much in the same manner as the embodimentsof FIGS. 2A and 2B, so that the ultimate structure will cure into asingle fused layer that can contain different biocides depending uponthe location depth within the fused coating. Furthermore, it is possibleto make this fused, impregnated anti-fouling bilaminar polymer layereither totally biocidal, for seriously bio-fouled waters and difficultapplications, or totally biostatic for less serious infestations or lesscritical applications.

This gives rise to additional structural arrangements of the biocideswithin the coating. For those embodiments that will contain both abiocidal Polymer-I and a biocidal Polymer-O layer, the embodiments willhave an immediate biocidal effect, killing larval forms includingveligers and cyprids as soon as they try to attach, rather than just abiostatic effect. If, in the relatively unlikely event that the outerbiocidal Polymer-O layer does not kill the invasive organism, the innerbiocidal Polymer-I will immediately kill the organism, as it would beextremely unlikely for the organism to be resistant to both biocidalbiocide compositions in the two separate layers.

Relevant to the increased potency of this enhanced antifoulingembodiment is the effect on the surrounding aquatic environment, whichplaces limits on what biocides can be safely used, as biocidal biocidescan come in contact with the surrounding aquatic environment.

FIG. 10B(1) shows a cut-away view of a structural embodiment of theanti-fouling coating where both the inner polymer layer Polymer-I 9 andthe outer polymer layer Polymer-O 3 are biocidal and where in thePolymer-O layer 3, the concentration of the first biocidal biocide 27(e.g., the anti-helminthic drug ivermectin), is present in a relativelyhigh concentration, and a second biocidal biocide 26 (e.g., theanti-helminthic drug, lufenuron 26) is present in a relatively lowconcentration. The Polymer-I layer 9 includes the second biocidalbiocide 26 in relatively high concentration and the first biocidalbiocide 27 in a relatively low concentration. 29A indicates the fusedinterface of the Polymer-O and Polymer-I layers.

For this embodiment to be environmentally favorable, since now abiostatic shielding effect covering the biocidal layer is not presentand the more potent biocidal biocide is now exposed to the water, thebiocide in contact with the water is made water insoluble. Bothivermectin and lufenuron share this physical property and so both aresuitable. Both may be substituted by other biocidal biocides as listedin the disclosure previously, for example, but any substituted chemicalcompound should have comparable or greater water insolubility. Forexample, suitable biocides may have a water solubility of less thanabout 20 mg/L, and preferably much less, as is the case of the twoexemplary compounds Ivermectin (4 mg/L) and lufenuron (0.06 mg/L).

Note that lufenuron is a halogenated organic biocide (it has twochlorine atoms), but it is still considered to be desirable for use withthe present invention. While under ordinary circumstances, chlorinatedorganic biocides are considered for the purposes of this invention toopotentially hazardous to other aquatic environmental organisms, thisexception can be made with lufenuron because it also has 8 fluorineatoms, which makes the compound so hydrophobic and water insoluble thatit would be highly effective as an on-contact biocidal biocide againstbarnacles, mussels, and other chitin-containing, shell-formingbiofouling organisms without any significant chemical leaching out intothe water.

Also it is important to note that virtually all members of the pyrethrinclass of biocides, when used in high concentrations as definedpreviously, especially with the adjunct compound, piperonyl butoxide,are biocidal and have water solubilities of up to over a magnitude lessthan even lufenuron and a KOC of greater than 100,000, and thus theywould be acceptable substitutes for either ivermectin or lufenuron inthis embodiment, as would any of the biocides listed in FIG. 21A, FIG.21B, and FIG. 21D. Coupled with the fused bilaminar fluoropolymercoating, this combination of two biocidal biocides will provide anextremely long lasting and extremely potent antifouling coating thatwill be environmentally safe. This embodiment would be for severefouling infestations or prevention of fouling in critical structuresthat are highly intolerant to even the slightest biofouling damage, andin areas where exposure of beneficial aquatic lifeforms is lessproblematical such as the interior of a large ship's plumbing system.

When the outer Polymer-O layer 3 is made biocidal in nature, otherconsiderations may apply. Under certain circumstances, a watersolubility of up to 100 mg/L may be acceptable when the biocidalmolecule is of high molecular volume with a high adsorption coefficient,KOC, indicating a tight affinity to the matrix into which the biocide isimpregnated. For instance, the macrocyclic lactone biocidal biocide,spinosad, which is a mixture of two compounds in a 5:1 ratio (similar tothe preferred biocidal biocide ivermectin used in many of theembodiments of this invention which is also a mixture of macrocycliclactones ivermectin 2-A and 2-B in a ratio of 4:1), and which is derivedfrom a bacteria used in fermentation of sugar cane to alcohol, but whichis not related to the ivermectin class of biocides, is an excellentbiocidal biocide for this purpose of a biocidal Polymer-I layer exposedto the water. It has a solubility of less than about 100 mg/L but a veryhigh KOC of 34,600 because of its huge molecular volume. Furthermore,spinosad has an especially low intrinsic aquatic hazard to otherlifeforms, particularly if spinosad D, if used as a purified preparationwith a decrease in the water solubility to an ultralow 0.33 mg/L,becomes a very desirable biocidal biocide. Numerous other exemplarysubstitutes listed in the tables of FIG. 21A, FIG. 21B, and FIG. 21C maybe used.

The outer and inner fluoropolymer layers are fused together in themanner previously discussed. FIG. 10B(2) shows a cut away view of ananti-fouling coating, again with two fused biocidal polymer layers, butnow with the concentrations of the biocides being reversed; lufenuron 26is present in high relative concentration and ivermectin 27 is presentin relatively low concentration in the Polymer-O layer 3 and ivermectin27 is present in relatively high concentration and lufenuron is presentin relatively low concentration in the Polymer-I layer 9. Thisembodiment, as in the case of the embodiment of FIG. 10B(1), may bedesired when the infestation is more severe and the structure is morecritical as far as anti-fouling damage. As in the case of FIG. 10B(2),being a reversal of compositions of FIG. 10B(1), FIG. 10B(4) showscompositions of biocides that are the reverse of FIG. 10B(3).

FIG. 10B(3) is a cut-away view that shows the same anti-fouling coatingstructure as FIG. 10B(1), except that now the two biocides are biostaticbiocides giving the anti-fouling coating a solely biostatic effect. Thesame relative concentrations of the two biostatic biocides as wasdescribed for the two biocidal concentrations in FIGS. 10B(1) and (2)are present. Preferred exemplary biostatic biocides may includecapsaicin 28 (whose water solubility is about 13 mg/L) as the firstbiocidal biocide in the in the outer polymer layer present in highrelative concentration along with cupro-nickel powder 29 (whose watersolubility is less than about 0.05 mg/L) in relatively low concentrationand in the inner polymer layer and in the inner polymer layer the secondbiostatic biocide, cupro-nickel 29 is present in a high relativeconcentration and the first biostatic biocide, capsaicin 28, is presentin a low relative concentration. As previously, the preferred ratio ofconcentrations is about 10:1 but may range from about 1:1 to about1000:1. Again, these preferred exemplary biostatic biocides can besubstituted with other compounds such as any of the pyrethrins in lowconcentration.

The water insolubility requirement for biostatic biocides is lessstringent then with the biocidal biocides because they are moreenvironmentally friendly, but solubilities of less than about 20 mg/Lare still the preferable attribute that is desired for this inventionfor the purposes of a long duration anti-fouling effect with lowleaching rates. Because biostatic biocide exposure to the aquaticenvironment is less potentially hazardous then biocidal exposure,biostatic biocides with water solubilities as high as about 100 mg/L,and especially those with a high KOC as low as 500, indicating a strongtendency for the biocide to remain fixed to the polymer matrix in whichthey are impregnated, are acceptable. Medetomidine has a watersolubility of 186 mg/L, which is higher than some of the biocides beingdescribed, but its extremely high fixation to the polymer matrixcompensates for the higher water solubility.

As in the case of FIG. 10B(2) being the reverse in terms of biocidalbiocide concentrations in the two layers of the configuration in FIG.10B(1), FIG. 10B(4) is the reverse in terms of biostatic biocideconcentrations in the two layers of the configuration in FIG. 10B(3).The embodiments of FIG. 10B(3) and FIG. 10B(4), as they are composed oftwo biostatic polymer layers, do not have as intense an antifoulingeffect as the embodiments of FIG. 10B(1) and FIG. 10B(2) composed of twobiocidal polymer layers, and thus wholly biostatic embodiments may beused for biofouling afflicted bodies of water where the infestation ismore mild in nature.

FIG. 10B(5) depicts a cut-away view of a fused bilaminar fluoropolymercoating that is completely biocidal in nature, but in this embodimentfirst biocidal biocide 26 is completely segregated to the innerPolymer-I layer 9, while second biocidal biocide 27 is completelysegregated to the outer Polymer-O layer 3, and both layers are biocidal.The advantage of this embodiment would be simplicity, cost savings,easier preparation and formation of the anti-fouling coating,preservation of the strongly biocidal character of the coating whichwould kill larval forms rather than inhibiting them or repelling them oncontact with the outer layer of the coating. Not shown is the reversecomposition embodiment of FIG. 10B(5), where the first biocidal biocide26 impregnates the outer layer 9 and the second biocidal biocide 27impregnates the inner layer 3, with the two layers fused together asexplained previously. Another important chief advantage of the presentembodiments is the greatly reduced chance of a resistant strain oforganism destroying the polymer antifouling layer. If, by chance, astrain of barnacles or mussels develops resistance to a given biocide,the second biocide deeper within the structure of the antifoulingcoating will likely eliminate the resistant invading organism. Thisprevention of resistance effect would be more enhanced with two biocidalbiocides as compared to two biostatic biocides.

FIG. 10B(6) depicts a cut-away view of an embodiment of the antifoulingcoating where the same biocidal biocide is in both the inner Polymer-Ilayer 9 that is fused by the method previously discussed to the outerPolymer-O layer 3. It is clear that by looking at FIG. 10B(1) that thehigh relative concentration of first biocidal biocide 27 can be keptconstant in Polymer-O 3, while the low relative concentration of secondbiocide 26 can be reduced to zero, creating a Polymer-O 3 that just hasthe first biocidal biocide 27 impregnated into it. In Polymer-I 9, thehigh relative concentration of second biocide 26 can also be reduced tozero while the low concentration of first biocide 27 can be increased toequal that of the concentration of first biocide 27 in Polymer-O 3,creating in effect a single, double-thickness polymer layer of firstbiocidal biocide 27.

In fact, a durable polymer layer of arbitrary thickness can be laiddown, impregnated with the single biocidal biocide by simply repeatingthe application of Polymer-O 3 without the low concentration of secondbiocidal biocide, similar to the process outlined in FIG. 1C. A similarprocess could be replicated with only using the second biocidal biocideand omitting the first biocidal biocide. The best applications for thisparticular embodiment would be for applications that require greatdurability and reasonable biofouling effectiveness to allow thatdurability to occur, where cost sensitivity is of high priority.

While it is not displayed in a figure, one further embodiment using justa single biocide, the embodiment of FIG. 1C where an individual polymerlayer may be built up of several separate coatings to produce a desiredthickness, and the features of FIG. 10B(6), is that a given polymerlayer, either Polymer-O 3 or Polymer-I 9, can be made of severalcoatings, with each fused coating being impregnated with a successivelyhigher (or lower) concentration of a biocide to produce a polymer layerwhose depth of concentration of the biocide varies on a continuing basiswith depth within the antifouling coating. Furthermore, this can be donewith each of several biocides at once, including the arrangement wheresome biocides are gradually increasing with the depth of the coating,and some are decreasing. In that manner, the basic embodiment of FIG. 1Aof this invention, when modified to accommodate the features of theembodiment of FIG. 1C and the embodiment of FIG. 10B(6), a single, fusedmulti-coating polymer layer is possible where, on a continuous basiswith depth within the antifouling coating, the biostatic biocidesdecrease (or remain the same) with depth away from the water and thebiocidal biocides increase (or remain the same) with depth away from thewater.

This produces a coating that either becomes more biocidal with depth andless biostatic with depth, or alternatively, can remain uniform incomposition with depth. Such a coating would be totally biostatic at thewater's surface, and totally biocidal at the surface being protected. Itis possible to apply this structural arrangement of continuously varyingbiocide concentrations to the Primer-I and Primer-O polymer layers aswell.

When the biostatic nature of the outer biostatic Polymer-O layer 3 ismodified to become biocidal like the inner biocidal layer in the mannerof FIGS. 10B(5) and (6), certain ramifications need to be considered.The embodiments of FIGS. 10B(5) and (6) shed the shielding effect of themore environmentally gentle outer biostatic Polymer-O layer 3 in keepingthe biocidal biocides away from the aquatic environment. Biocides inhigh concentration would then be in direct contact with the aquaticenvironment. To negate any possible effect on that environment, thebiocides in the anti-fouling coating would be selected for favorableHiguchi Model physical properties as explained above, so that theleaching rate of the biocidal biocide or biocides, as predicted by theHiguchi Model, would be very low, keeping benign and beneficial aquaticorganisms free from potential negative environmental effects.

In terms of the polymers that can be used in the current invention, thepresent embodiments specify that the polymers come from the list definedin the section on polymers described above. Any polymer, of eitherplastic or non-plastic type, and of rigid, semi-rigid, or flexiblenature may be used in the polymer layers of the antifouling coatingdescribed in this invention. The previously specified list is notall-inclusive and any other suitable polymer may be used instead.

Two polymers of the class of polymers known as fluoropolymers inparticular stand out as especially preferable for the current invention.The first is the class of compounds known as flourourethanes. Theseespecially durable polymers have been tested under marine conditions andwere found to have a durability exceeding 10 years and up to 15 yearswhen applied to boats and ships. The second polymer isflouro-ethylene-vinyl-ether (FEVE) and its related polymers. When FEVEwas coated onto bridges, it was found that the polymer could protectthem from corrosion for at least 25 years, with some estimates as highas 100 years, and while these numbers would be expected to be shorterwith continuous immersion in marine environments, a life expectancy ofdurability would be expected to be at least as great as theflourourethanes, and most likely even longer.

Both classes of polymers, because they are highly fluorinated and, to adegree, chemically related to PerTetraFlouroEthylene (PTFE), haveexceedingly low coefficient of friction numbers associated with them,giving these polymers an inherent ability to shed biofouling invasionsof protected surfaces coated with them as long as the surfaces weremoving at sufficient rates of speed relative to the water at least asignificant fraction of the time they were in the water. If calcareouscalcium forming invertebrate biofouling species were not a problem,these two classes of coatings, once applied to the protected surfacessuch as the hull of the ship would be expected to last for a decade.

However, once biofouling organisms make their presence known in thesurrounding marine environment, and they are expected to attach and formdestructive biomasses since the hard protective coatings formed by thesepolymers are quite attracting to such biofouling organisms, unless theprotected surface moves frequently at high velocity through the water.When these otherwise extremely hard, smooth, and durable fluoropolymersurfaces are colonized by biofouling organisms, they degrade and aredestroyed quickly by the relentless borrowing and destruction of theinvertebrate's shell as it pierces not only the fluoropolymer coatingbut also the protected surface underneath. As a result, the biofoulingorganisms also quickly destroy the protected surface underneath fromboth bio-corrosion of the fouling species, but also chemical andgalvanic corrosion of the protected surfaces underneath once access tothe surface has been established by the water, especially seawater.

Thus even when fluoropolymers are used, when biofouling is present bycalcareous invertebrate animals, the extremely long durable life ofthese fluoropolymers cannot be realized and old coatings have to bescraped off along with the barnacles and mussels and algae, and newcoatings have to be applied to the submerged surface like a ship's hullat a frequency similar to that of non-fluoropolymer coatings.

It is the combination of fluoropolymers with multiple biocides,segregated and impregnated into layers of such fluoropolymers asdepicted in structural embodiments depicted in FIGS. 1A, B, and C; C;2A, B, and C; 5A and 5B; 6A and 6B; 7, 8; and 10A and B, that canproduce such potent anti-fouling coatings that can be durable andeffective over a long, multi-seasonal period of time, probably as longas a decade or longer. Furthermore, another major benefit offluoropolymers are their excellent resistance to UV radiation.Fluoropolymers do not go brittle and deteriorate like other plasticpolymers with prolonged exposure because of the high energy of thecarbon-fluorine bond, as opposed to the carbon-hydrogen bond of mostnon-fluorinated plastic polymers. While submerged, only a small portionof UV radiation is absorbed by the water, so UV resistance is anecessary requirement of any coating.

For massive steel structures, such as bridges, oil platforms, and offshore wind turbines, the need to prevent corrosion is a major problem.It has been shown in Europe and Asia that oil platforms and bridges canbe protected for at least 25 years, without the need for repainting,when a fluoropolymer coating such as FEVE is coated onto such structureswith a zinc-rich primer to enhance adhesiveness between thefluoropolymer and the steel. For a thick steel structure, if a Primer-Iinner primer coat of zinc-rich primer is applied to a suitably preparedsurface, like a sandblasted ship's propeller, and a fluoropolymer innerbiocidal Polymer-I layer undercoat, impregnated with the biocidecompositions of the present embodiments, is coated onto the zinc richprimer, and then subsequently a fluoropolymer outer biostatic Polymer-Otopcoat is added impregnated with the biocide compositions of thepresent embodiments, to produce the exemplary structure of FIG. 1C withor without an outer Primer-O coat, an anti-fouling effect on a ship'ssteel propeller or hull can be achieved that could easily last 10 yearsand perhaps far longer.

Clearly, however, if such coatings are applied, any damage to thecoating as a result of a collision or accident with an object in thewater would have to be repaired immediately. Using other types ofdurable epoxy primers, such durable anti-fouling coatings can be appliedto aluminum, stainless steel, brass, bronze, wood, and plastic or anypolymer structures, subject to any constraints involving possibleunwanted galvanic action between the antifouling coating and theprotected surface. It is also possible to impregnate the biocides of thePolymer-I layer into the zinc-rich or other types of epoxy polymercoatings, the Primer-I layer, so that the Primer-I layer and thePolymer-I layer become one and the same, giving beneficial rise to apropeller anti-fouling coating structure of only two layers.

Another advantageous use of this long-lived coating structure is theboat house. Boat houses, by their nature of being large, massive, andstationary objects, are difficult to get out of the water formaintenance in scraping of barnacles and mussels off their hulls,refurbishing their hulls, and repainting their surfaces. The presentembodiments provide durable, low-maintenance hull coatings to help solvethis problem.

Movable oil rigs are susceptible to new invasive species, such asseveral species of invasive shrimp and invasive crabs, among the morecommon forms of biofouling. These massive structural forms, likecommercial seagoing vessels, have to be brought out of the waterperiodically and refurbished to remove the accrued biomasses. At least adozen new organisms, virtually all of them being crustaceans that arechitin- and calcium-forming, have invaded areas of the ocean where thesestructures were brought into port for maintenance, resulting in localinfestations that are expanding in area. Compounding the problem is thatthese creatures are not sessile and stationary, like invertebrateshell-forming organisms, but rather they are vagile and constantlymoving among the sessile biofouling community implanted on the oil rig.They do not propagate by larval forms, such as cyprids and veligers thatare seen with proliferating barnacle and invasive mussel speciesrespectively, most of which die before attaining a site favorable forimplantation and growth, but rather the whole organism removes itselffrom the oil rig and spreads into the non-native waters through whichthe slowly moving oil rigs are drawn the way to its maintenance station.

Furthermore although ships are more numerous, oil platforms tend to havea higher percentage of fouling cover—the entire surface of the oil rigusually gets bio-fouled, usually an area over about 5000 m2 on a typicalrig. Commercial shipping vessels are larger, with container shipsgenerally having about 7,000 to about 14,000 m2 of wetted area, but lessthan about 1% of the typical hull is fouled. The greater extent ofbiofouling on movable oil platforms may be due to being deployed andmoored in stationary position for extended periods of time, as well asthe fact that ships are moving through the water at considerablevelocity, making it more difficult for a biofouling organism to get ahold.

At this time there has been no effective solution to this recentdevelopment of a new type of biofouling. However, the presentembodiments are particularly appropriate for this problem, as theytarget all types of organisms that are members of the animal phylum,Arthropoda. Invasive shrimp and crabs are crustaceans, like barnacles,and thus any biocidal structures and compositional embodiments thatwould be effective against barnacles and invasive mussels will also beeffective against this new form of biofouling. In this particularapplication, the current invention would be targeting organisms that donot spread by attachment of free floating larval forms that settle andattach on hard submerged surfaces, but instead those that prefer to movearound on them. Thus the biostatic nature of the outer biostaticPolymer-O layer can be modified to become biocidal, like the innerbiocidal layer in the manner of FIGS. 10B(5) and (6).

These two embodiments should be particularly efficacious for thisproblem, as the mobile invasive biofouling organisms would be killed oncontact upon settling into position onto the mobile oil platform. Whiletheoretically, some beneficial crustacean shrimp and crabs might beaffected if they attempt to settle onto the oil platform, the vastnumber of them would stay on the ocean floor, away from the oil rig, andwould not be affected as the biocides kill on contact with the surfacerather than being released into the ocean. Furthermore, even though theembodiments of FIGS. 10B(5) and (6) shed the shielding effect of theouter Polymer-O layer in keeping the biocidal biocides away from theaquatic environment, the biocides in the anti-fouling coating would beselected for favorable Higuchi Model physical properties so that theleaching rate of the biocidal biocide or biocides would be immeasurablylow, keeping benign and beneficial aquatic organisms free from potentialnegative environmental effects.

On the other hand, the multi-year durability required of theapplications enumerated above is sometimes not required. For example,with anti-fouling coatings for high-speed power and racing boats, whereit is absolutely necessary to maintain the coating to a high speedmirror finish, requiring frequent polishings during a boating season,the coating is often replaced yearly to maintain maximum low-frictionperformance. The coating thus not only provides anti-fouling protectionto such a boat's surface, but also provides the lowest coefficient offriction between the speeding boat and the water flowing past.

The fillers described above are selected for increasing durability,adhesion, and complying with color pigment requirements. A group offillers and additives may also be used that lower the friction of thesurface of the Polymer-O layer with the surrounding water. These fillersinclude PTFE, molybdenum disulfide powder, non-cubic boron nitride,graphite flakes, silicone powder and graphene nano-platelets, grapheneoxide, and graphene fluoride. Note that boron carbide exists in twostructural forms, the cubic form which used as an abrasive andwear-resistant substance as it is the second hardest substance known tomankind, and a soft non-cubic form which has lubricating propertiessimilar to that of graphite. Hence boron nitride is a member of both thehard, abrasive wear-resistant filler group and the soft,friction-reducing filler group. The preferable particle size would beless than about 50 microns and the smaller the particles, the moreadvantageously friction with the water will be reduced.

Using a filler that includes a mixture of PTFE, molybdenum disulfide,and graphene nano-platelets, a mixture that has remarkably highlubricity and low static and dynamic friction, the filler mixture isadded to the outer biostatic Polymer-O layer to would give this layer,and thus this embodiment, a low coefficient of friction that would beused to advantageously increase the speed and efficiency of highvelocity water vessels such power, speed, and racing boats in additionto the reduction of friction produced from the prevention of foulingorganism attachment. Furthermore, an algaecide may be added to thePolymer-O layer, as now attached algae, which can form and attach withinone week, is not only a cosmetic nuisance, but also a friction-inducingfactor.

Note that in this case, a shorter operational life of one boating seasonis acceptable. Instead of using the fluoropolymer as the coating matrixpolymer itself, a short durability paint like a rosin paint or asilicone paint and the fluoropolymer, PTFE, may be used as a lowfriction filling agent rather than as the coating. The silicone paintpolymer, if used in the Polymer-I and Polymer-O layers, will further addto the anti-friction effect of the special low friction fillers. Thisshort operational-life embodiment is designed specifically for highvelocity water vessels such as speed, power, and racing boats as well aspersonal high speed Sea-Doo® type water sleds, as the ultralow frictionof this coating, achieved from the summation of a low-friction polymercoating, friction-reducing mixture of special low friction fillers, andprevention of biofouling attachment to the boat's surface from theantifouling coating, is more beneficial to this category of boatoperation then a long multi-year operational life.

The percentage by weight of the Polymer-O low friction layer from thelow friction fillers is preferably less than about 20% in the aggregate,though the range may be as high as up to about 50%, less the combinedweight percentage by weight of the algaecide, the biocidal biocide, andthe biostatic biocide. The coating of both the low-friction, outerbiostatic Polymer layer and the inner biocidal Polymer-I layer rangesfrom about 5 mils to about 200 mils thick, depending upon the number ofcoatings of each layer are employed, similar to the physical thicknesscharacteristics of all of the embodiments of this invention, with thicklayers being built up of one or more coatings of the biocide impregnatedpolymer.

FIG. 10C, which depicts a cross-section of the structural anti-foulingcoating, giving a structural representation of this low-frictionembodiment that is suitable for high velocity leisure and racingvessels. Inner biocidal Polymer-I layer 9 is depicted as before, with ahigh relative concentration of biocidal biocide 4 and with a lowrelative concentration of biostatic biocide 5. Outer biostatic Polymer-Olayer 3 is depicted with a high relative concentration of biostaticbiocide 5 and a low relative concentration of biocidal biocide 4. Inthis embodiment, Polymer-O 3 also contains the algaecide 26 in the formof zinc pyrithione or another metal salt or mixture of metal salts ofpyrithione (Pn), as well as several fillers to enhance Polymer-O's lowfrictional nature against the rapidly moving water 2 that faces theaquatic surface 1 of Polymer-O 3. These low-friction filler particles ofbeneficial size less than 50 microns include PTFE (PT) 28, molybdenumdisulfide 25, and graphene nano-platelets 27 and are all simultaneouslyused by the Polymer-O layer 3 to reduce the friction between the waterand the antifouling coating. The protected surface is 19.

One advantageous aspect of this particular application is that, becausehigh speed power and racing boat operators require their boats to bepolished to maximum perfection on a weekly basis, a new layer ofbiocides and friction-reducing lubricants is exposed to the water aftereach polishing, keeping the low-friction properties and anti-foulingorganism attachment inhibition of the outer biostatic Polymer-I alwaysat a maximum with time. In effect, this polishing process acts like asoft abrasive paint, but the paint fragments are not released with timeinto the aquatic environment. Instead, the paint fragments are discardedin a safe manner on land.

In the laboratory, it has been shown that the combination of graphene,in the form of graphene nano-platelets, and PTFE, in the form of apowder, with further enhancement by molybdenum disulfide, a potentlubricant in its own right, has worked exceedingly well to reducefriction between sliding surfaces. When the sliding surfaces are waterand a smooth surface that includes a silicone polymer or rosin polymer,with the mixture of PTFE powder and molybdenum disulfide lubricantfillers, its lubricity now enhanced by the further addition of graphenenano-platelets, the low frictional advantage exceeds previouslydescribed formulations for anti-fouling coatings. These low-frictionmaterials have not been incorporated into polymers that are alsoimpregnated with compositions of graphene nanoplatelets and mixtures ofbiocidal and biostatic biocides. The result is an antifouling coating ofexceptionally low frictional resistance.

For applications other than high speed boating, which do require ananti-fouling coating with long durability and operational life as wellas an extremely low coefficient of friction with the aquaticenvironment, the silicone or rosin polymer of the Polymer-O layerdescribed for this particular embodiment used in competitive boat racingmay be substituted with the polymer family most preferred with thepresent invention for long duration operational life, thefluoropolymers, including flourourethanes, flouro-ethylene-vinyl-ether(FEV) and similar chemical structures. Such a coating will have anultra-low frictional resistance, an ultra-long mechanical durability, anultra-long anti-fouling effectiveness, an ultra-wide spectrum ofanti-fouling effectiveness, and ultra-safe environmental compatibility.

Referring again to FIG. 10B(6), with reference to FIG. 10B(1), the highrelative concentration of first biocidal biocide 27 can be kept constantin Polymer-O 3 while the low relative concentration of second biocide 26can be reduced to zero, creating a Polymer-O 3 that just has the firstbiocidal biocide 27 impregnated into it. In Polymer-I 9, the highrelative concentration of second biocide 26 can also be reduced to zerowhile the low concentration of first biocide 27 can be increased toequal that of the concentration of the first biocidal biocide 27 inPolymer-O 3, creating two polymer layers of the first biocidal biocide27. Furthermore, if Polymer-O 3 is applied shortly after Polymer-I isapplied and is still tacky and partially uncured, the Polymer-O 3 andPolymer-I 9 will fuse into a single, uniform layer of extra thicknesscontaining a high relative concentration of the first biocidal biocide27. A similar transformation of FIG. 10B(1) into FIG. 10B(6) can producea single fused layer of extra thickness of a high relative dose of thesecond biocide 26. The fusing of the Polymer-O and Polymer-I layer,together containing a high concentration of just one biocide, now givesrise to another major use for the anti-fouling coating, thoseapplications that require the ultimate in simplicity with respects tothe logistics of applying the coating.

The problem of already established massive biomasses of foulingorganisms that are so extensive, or are located in areas where theysimply cannot be scraped off, remains an unsolved problem. This isparticularly the case with invasive mussel species like the quaggamussel, the zebra mussel, and Mediterranean mussel than it is withbarnacles, because the invasive mussels can cover, as was alreadypointed out, vast geographical areas such as the floor of the GreatLakes, Lake Mead, and Lake Powell in the US, can cover entire beaches,the surfaces of locks on freshwater canals, and other publicrecreational facilities. The continued presence of these massivebiofouling deposits leads to the continued contamination of inland freshbodies of water by the prodigious release of larval forms, by themillions per mussel, up to several times per year, with mussel densitiesas high as thousands per square meter. A continuing and spreadinginvasive mussel problem is the result. While chemical dispersals intosmall lakes have occasionally brought limited success, the intimateconnection between most lakes of significant size and the human watersupply and the human recreational environment and other uses simplymakes this solution untenable. It is believed that an application andembodiment of the current invention represented by FIG. 10B(6) would bea safe and effective way to address this problem.

Referring now to FIG. 10D, a mass 35 of invasive mussels is showntotally infesting and coating a surface which can be any natural orartificial surface whose size, location, and surface characteristics aresuch that the mussels cannot be scraped off and killed. Most of thebiomass is dead, as more recently proliferating mussels smother andasphyxiate mussels located deeper in the biomass resulting, in a thinrim or coating of live proliferating mussels 37. The anti-foulingcoating can be applied as a coating 36 to the top layer 37 of musselsthat are exposed to air, water, and nutrients and are therefore,thriving. The coating will interact and entangle with the feedingstructure mechanism of the mussels 37 and cause them to starve to death,and deprivation of their oxygen supply will cause them to asphyxiate.They will also be killed by the direct biocidal chemical effects onthem.

It is estimated that within days, the entire biomass of mussels will bekilled. On vertical surfaces they will be either sloughed off or form aninert exoskeleton where, if in a lake or river, beneficial life formswill colonize, and on horizontal surfaces like beaches, they willdecompose, loosen their grip, and can either be left to disintegrate orthe dead biomass can be carted away. There will be no more massivepopulations of live mussels other than a few survivors, and those fewmussels that survive and the relatively few larvae forms they producewon't be able to attach because of the presence of the coating, and theywill soon die. The proliferative chain of events leading to continuedspread of the invasive mussels will be broken.

The application of the Polymer-I biocidal coating could be repeatedmultiple times in quick succession to produce a fused biocidal layer ofconsiderable thickness in the manner of FIG. 10B(6) but onlysufficiently thick to accomplish the necessary mussel eradication fromthe beach or lake bed or as needed to assure the most completeextermination of the invasive mussels. Alternatively, multiple coatingscan be spaced out and applied to the encrusted surface at widely spacedintervals as separate applications as required to control the biofoulingmasses.

Depending upon the nature of the structure encrusted with mussels, thepolymer used in the Polymer-I application can be adjusted. If thestructure is an underwater lake, pond, or river bed, underwater curingepoxy polymers impregnated with the required specified biocides and withthe longest possible operating life and highest durability can be used.Only those biocides with the lowest Higuchi Release Factors that aredeemed safe enough for the human water supply and the human food chainwould be used. Ivermectin of lufenuron for instance would result invirtually no biocidal levels in the water and the miniscule amounts thatare released over time are UV degradable quickly over short periods oftime.

Contrast this mode of application with the prior attempts made atsterilizing lakes of mussels by the dumping of insecticides directlyinto the lake. If the mussel-encrusted surface is a partially submergedsurface, like a canal lock, the canal lock can be emptied of water forseveral hours while its mussel encrusted surface is coated with thePolymer-I anti-fouling coating (the Polymer-O coating is not needed onany of these applications, as the mussels are already in adult form andencrusted and just repelling larval forms would not be of muchadditional use. Again one would want to use polymers that would make theanti-fouling coating for these structures as durable and as long actingas possible.

However, a beach is an exceptional case where one would want to use aPolymer-I coating of transparent polymers that are short-lived and aredesigned to break up in ultraviolet light of the sun after a shortduration of time, so that the beach returns to its normal consistency inthe shortest period of time. For the beach application, the polymerwould have to be either able to cure in a damp environment, or capableof underwater curing, or be rapidly curing so that the polymerantifouling coating could be applied to the encrusted mussels soon afterlow tide begins and the curing process is completed before the arrivalof the next high tide. The biocides themselves would be chosen to beconsistent with the needs of the present embodiments and according tothe specified physical and chemical requirements of the application,which will result in a very high degree of human and environmentalsafety with very low biological risks either to humans and their waterand food supply, or other beneficial animals in the aquatic environment.

The biocide used would have the property of being able to be broken downby ultraviolet light. A representative example of a suitablepolymer-biocide combination for this application would be rapidly curingtransparent epoxy coatings impregnated with ivermectin in the previouslydescribed weight compositions. Both the transparent epoxy and theivermectin molecule are highly and rapidly degradable under sunlight andultraviolet light. The thickness of the coatings used would vary fromabout 5 to about 200 mils depending upon the extensiveness of theencrustations.

Theoretically, the embodiment of this invention that would be used toannihilate the population of living invasive mussels from largestructural surfaces and areas that have been contaminated and encrustedwith large biomasses such as beaches, canal locks, piers, docks, andlake and river bottoms can be also applied be applied to barnacleinfestations. However, since a barnacle infestation has exposure to thehuge bodies of water represented by oceans, rather than the case of aconfined and contained fresh body of water of relatively smaller size, asuccessful result would be more difficult to achieve.

Once a large mussel-encrusted area is successfully sterilized, whichshould not take more than a few weeks, one must next allow forpreventing the layer of encrusted dead mussels from providing anexcellent surface for newly arriving mussel larval forms that willrestart the entire problem all over again. If the encrusted area is anarea that is accessible and amenable for the mechanical stripping andcarting away the dead mussels, then that would be the most preferredoption. If it is a submerged, manmade structure such as a canal lock,the mussels can be stripped off, and the surface repainted with thepresent antifouling coating. However, if the encrusted area is a lake orriver bottom, the preferred option would be to coat the dead mussellayer with the Polymer-I layer on it with a Polymer-O layer, again usinga polymer capable of underwater curing, and impregnated with any of thepreferred biocidal compositions that could comprise the Polymer-Obiostatic layer of the current invention, with the added proviso thatthe chosen biocides would have to be absolutely safe for the human watersupply and recreational water resources, using safe biocides such ascapsaicin in the Polymer-O layer.

Application of a Polymer-O layer to the dead encrusted mussel layercoated with the previously applied Polymer-I layer will, in effect, coatthe lake or river bottom with a durable antifouling coating which willrepel and prevent further veliger larval settlement, thus breaking theproliferative life cycle of the invasive mussel, thereby bothsterilizing that body of water of live invasive mussels, and preventingthe spread of the infestation to other bodies of water.

Though the emphasis to this point has been on rigid surfaces, theembodiments of this invention extend to the protection of semi-rigidsurfaces and structures, and even flexible surfaces and structures. Ifthe polymer being used is a flexible polymer, such as a rubber, and itis impregnated with biocides, and it can be coated on such a flexiblesurface, the anti-fouling protection that the present embodiments affordcan be applied to semi-rigid and flexible structures.

For instance, the non-plastic flexible polymerethylene-propylene-diene-monomer (EPDM) has a lifetime of 25 years whensubmerged in marine conditions, and even longer in freshwaterenvironments. It is applied as a liquid coating and then it is allowedto cure to a hardened, but flexible, polymer. EPDM is immune to UVlight, chloride ions, and significant temperature extremes. It also hasa modulus of elongation of about 200% to about 300%, so that it may bestretched like a spring, with a restorative force bringing it back toits original conformation and shape. If impregnated with biocides in themanner of this invention, it can give anti-fouling protection to avariety of flexible and stretchable materials and structures.

Referring now to FIG. 11A, a propeller is shown, onto which theanti-fouling coating is applied. Propellers can be made up of anyappropriate material including, e.g., cast iron, steel, ceramics,aluminum, brass, fiberglass, stainless steel, or even wood. Barnaclesand invasive mussels are especially problematic here, as the boat'spropulsion through the water is generated by the propeller moving athigh velocity against the water. Increased friction by mussels andbarnacles here greatly can increase fuel consumption, slow the speed,and eventually destroy the propeller.

Furthermore, irregularities on the propeller blades due to adultbarnacle and invasive mussel shells can create tremendous turbulence andcavitation, leading to vibrations up the propeller shaft, which candamage and destroy the engine proper. Stainless steel, even 316 type,thought to be relatively resistant to barnacle growth, and thought bysome to be an expensive solution to biofouling, actually is noteffective because of 3 mechanisms. First, the barnacle shell grows intothe steel, resulting in pitting that allows chloride corrosion bydestroying its protective passivated layer of chromium oxide. Second,the barnacle glue and byssel thread etches into the stainless steel anddestroys its passivating protective layer because of the corrosiveproperties of the glue. Third, barnacle metabolism removes oxygenlocally from the seawater, which is necessary for maintenance of thepassivated chromium oxide layer. Invasive mussels also have bysselthreads and mussel glue that cause the same problems, although the freshwater habitat of mussels does not involve chloride ion corrosion.

All three mechanisms result in chloride corrosion of the stainless steelin seawater by barnacles, while mussel glue corrosion and oxygendeprivation corrosion occur in freshwater. The only solution is to stopthe biofouling infestation at the Stage 0 settlement and attachmentstage, or at the latest, the Stage 1 metamorphosis and juvenile stage.

In FIG. 11A barnacle cyprids in salt water 110 and mussel veligers infresh water 111 are seen floating in the water and are prepared toattach themselves to the propeller 115, to which the anti-foulingcoating 116 is applied. Coating 116 is blown up in the inset drawing toreveal the propeller surface to be protected 19, inner biocidal polymerlayer Polymer-I 9, and the outer biostatic polymer layer Polymer-O 3.Anti-fouling coating 116 is further blown up in FIG. 11B to reveal acut-away view similar to previous structural embodiments.

Biostatic larval attachment inhibition is provided by Polymer-O 3, whichmay include a fluoropolymer such as a flourourethanes, or FEVE, andwhich may be impregnated with a high relative concentration of abiostatic biocide 118 such as purified capsaicin (CA) and a low relativeconcentration of a biocidal biocide 119 such as ivermectin (IV). Thebiocidal killing function is provided by Polymer-I 9, which isimpregnated with a relatively high concentration of the biocidal biocide119 and a relatively low concentration of the biostatic biocide 118. Theboundary 117 between Polymer-O 3 and Polymer-I 9 is shown, as is theaquatic environment 2, and the propeller surface 19 and structureitself.

In addition, Polymer-O 3 is also impregnated with particles of boroncarbide 119A between about 1 and about 100 microns in size with anoptimal range of about 7 and about 50 microns to increase the adhesionof the Polymer-O layer 3 to the propeller 19. The polymer component ofPolymer-I 9 is not a fluoropolymer but rather may be an epoxy resinadhesive primer of high adhesive strength to create as strong as bond aspossible for the coating to the propeller, as that coating is subjectedto tremendous frictional forces and centripetal forces of the rotationof the propeller, as well as the forward velocity of the boat or ship.

In this application the Polymer-I layer 9 and the Primer-I layer are onein the same, and this single layer performs the dual functions of abiocidal polymer layer and a primer polymer layer, giving theantifouling coating a dual layer structure. If the propeller is made ofcast iron or a steel alloy, the Polymer-I primer is preferentially azinc-rich inorganic or organic epoxy primer for long life. If in thisapplication the Polymer-I 9 were structured to be a separate layer fromthe Primer-I coating because a separate inorganic zinc-rich primer isused, the antifouling coating would be a three-layer structure ratherthan a two-layered one.

The low frictional nature of Polymer-O 3 in a two-layer antifoulingcoating improves the efficiency of the propeller from reduced frictionand the durability of the antifouling coating. In a three-layerantifouling unit, a fluoropolymer layer of the Polymer-O layer 3 againimproves the efficiency of the propeller from reduced friction, and thetwo layers of the fluoropolymer comprising both Polymer-O 3 andPolymer-I 9 greatly enhance the durability of the antifouling coating.Frictional forces can be reduced even further with the addition ofcombinations of various low friction fillers from the group previouslydescribed, and the preferred combination of PTFE powder, molybdenumdisulfide powder, and graphene nano-platelets being particularlyeffective in this regard.

Referring now to FIG. 12, the application of a fiberglass resin“Gelcoat” to a fiberglass boat hull is shown. FIG. 12A depicts acut-away view of boat hull 19A with its interior surface 19B facing theinterior of the boat. The boat hull 19A is coated with an inner bottomcoat Polymer-I biocidal layer 9 whose polymer can be a preferred resinpaint or any other type of paint. It is impregnated with a high relativeconcentration of a biocidal biocide and a relatively low concentrationof a biostatic biocide. The Polymer-I layer 9 is covered by an outertopcoat of Polymer-O biostatic layer 3 that includes a polymer of theresin polymer category that ordinarily would be used in “Gelcoat” finalouter coatings of boats when they are first manufactured. The Polymer-Olayer 3 is impregnated with a relatively high concentration of biostaticbiocide and a relatively low concentration of biocidal biocide. The“Gelcoat” is most often comprised of fiberglass resin but may be formedfrom any appropriate polymer. The boundary 120 between the fiberglasshull and the Polymer-I layer 9 is shown, as is the boundary 121 betweenthe Polymer-I layer 9 and Polymer-O layer 3, the aquatic environment 2,and the water surface side 2A of Polymer-O 3. A transparentfluoropolymer may be substituted for the fiberglass resin “Gelcoat”.

Referring now to FIG. 12B, the same cut-away structure is shown as inFIG. 12A, but with the inclusion of an inner primer polymer layer 124.FIG. 12C shows an embodiment where the fiberglass hull itself is part ofthe anti-fouling coating. At the time of manufacture, the biocides areadded to the fiberglass at the time the boat hull is molded ormanufactured. It is important that the boat hull always be biocidal, asany barnacle or mussel that might penetrate the outer polymer coating“Gelcoat” would be highly destructive to the boat because the boat hullitself would be the next polymer layer invaded.

Boat hull 19A (also labeled as 9) with its inner surface 19B facing theinterior of the boat is impregnated with a relatively high concentrationof a biocidal biocide like ivermectin 4 and a relatively lowconcentration of a biostatic biocide such as purified capsaicin 5.Essentially the fiberglass boat hull has become biocidal inner polymerlayer Polymer-I 9. The process of adding biocides to fiberglass resincomposites at the time of manufacture has been described schematicallywith FIG. 2B and the description associated with FIG. 2B. The boundarybetween Polymer-O and Polymer-I is 121. Polymer-O is now the “Gelcoat”,that may be transparent or colored if pigment is added to it, againwould be comprised of fiberglass resin, or as a substitute, afluoropolymer, or any other suitable polymer, and would be impregnatedwith a relatively high concentration of biostatic purified capsaicin 5and a relatively low concentration of biocidal ivermectin 4.

In addition, an algaecide, a metal salt pyrithione (PY) 123, has beenoptionally added to Polymer-O 3. Prevention of algae accumulation on theboat, though easily removed and not responsible for anywhere near thefunctional friction problems and structural damage as seen with theinvertebrate calcium forming organisms, nevertheless is a cosmeticfeature desired by most luxury boat owners. Cosmetic appearance would beless of a concern for large commercial vessels.

FIG. 13A, B, C depict high risk applications where the use of thebiofouling coating of this invention may not only protect vital marineand fresh water structures from malfunction and destruction, but alsomay slow the contagious spread of invertebrate species biofouling causedby the larval contamination of these structures, especially in inlandbodies of water where leisure boats are brought from location tolocation, and in ocean bodies of water where spreading the contagiousmussels in fresh water and barnacles in salt water occurs due to larvalcontamination of bilge pumps and ship plumbing systems.

FIG. 13A shows a leisure boat 156 and all of the structures at risk forbiofouling where the use of the biofouling coatings of this inventionwould prove applicable. Shown is anchor 130 (not seen under the boat),bilge 131 and live wells 132 (not shown in interior of the boat),propeller 133, storage compartments 141 and dock lines 140 (not shown inthe interior of the boat), motor intake 134, wheels and wheel axle 135,hull 138 and roller bunks 136. Boating transport accessories subject tobiofouling infestations include hitch 139, and trailer 137.

Even if no visible barnacles or mussels are seen on these structureswhen transporting boats from one body of water to another overland,movement of leisure boats can transport invisible veligers and cypridson their surfaces, which can resist desiccation for up to several dayson damp surfaces, or they can contaminate bilge areas, allowingcontagious spread to unaffected bodies of water. If a lake is infectedwith quagga mussels or zebra mussels, the water may be infected with upto hundreds of thousands of veligers per cubic meter that willcontaminate surfaces as they are removed from the water for transport.All of these listed structures are amenable for the anti-fouling coatingof this invention. Such spread of biofouling organisms through theirlarval forms can be totally prevented with this type of anti-foulingcoating. The damage to all of these listed structures on the boat interms of corrosion from invertebrate biofoulers as well as malfunctionof engines, other boating parts, loss of speed, and increased fuelconsumption are all completely preventable. Correction of these problemson a global scale with transoceanic shipping vessels will markedlyreduce carbon emissions, reduce fuel consumption, and ameliorate one ofthe factors causing global warming.

FIG. 13B shows a schematic drawing of a hydroelectric plant. Dam 142sends water via its outtake channels 143 to hydroelectric generators 144and the used water is emptied downstream by exit pipes 145. Throughoutthe water flow path through structures 143, 144, and 145, as well asintake grates and filters (not shown), this anti-fouling coating can beapplied to prevent biofouling accumulation which can otherwise blockwater flow, reduce electrical energy generation, and most importantly,damage expensive hydroelectric generators if anti-fouling organismsproliferate within these apparatuses. Also, one must note thatproliferation of organisms in these locations increase the spread ofveligers of invasive mussels to spread the contamination downstream.

FIG. 13C depicts a schematic drawing of an off-shore wind wave energyharvesting farm that serves as an application embodiment of the currentinvention. There are two wind turbines 147 supported by two pylons 146resting on seabed 155. A wave energy converter includes a buoy 148floating on the surface of the ocean 151 in motion (indicated by arrows157B) from the passage of waves acting through a mass spring system madeup of springs 149 and 154, which move a linear electric generator 157Awith metal enclosure 152 in synchrony with the passage of ocean waves.The generator is held in place by braces 156 connected to the pylons ofthe wind turbines and two circular slide bearings 157 through which thegenerator slides in a vertical oscillatory linear motion in synchronywith the waves. Since this would be considered a marine installation,barnacles inevitably will try to attach and grow. All the structuresoutlined in dotted lines are subject to damage by barnacles.

While the pythons would sustain surface corrosion damage, because theyare massive and stationary, the barnacle problem would be limited toexpensive periodic scraping maintenance sessions. However, with the waveenergy converter, barnacles getting onto moving bearing surfaces 158will destroy the generator, and barnacles getting onto the bottom of thebuoy, spring 154 and cable 153 and stretchable cable 153 will add weightto the generator, effect the buoyancy of the float, and impair thetransmission of the energy of the waves down to the generator as well aspossible rupture of the cables. While this wave energy generator is anexemplary structure, wave energy generators of all types and mechanismsare subject to malfunction and early lifetime termination from barnacleattachment and growth. Application of the present embodiments to all ofthe structures outlined with a dotted line on FIG. 13C would preventthese problems for an extended period of time.

FIGS. 14A(1), (2), and (3) depict cross-sectional and longitudinal sideviews of pipes whose surfaces are protected from fouling by anapplication embodiment of the anti-fouling coatings comprising thisinvention. FIG. 14A(1), upper diagram, depicts a cross-sectional view ofpipe 160 surrounded by non-contaminated water or other material inexterior space 166, which may include plastic such as PVC, or metal suchas copper, stainless steel, titanium or other suitable corrosionresistant metal or alloy.

Pipe 160's inner surface 160A is exposed to water 2, which iscontaminated with either barnacle cyprids or mussel veligers 165. Thepipe's inner surface 160 is coated by an inner polymer layer, Polymer-I9, that is biocidal (4) in nature. In turn, Polymer-I 9 is coated by anouter polymer layer, Polymer-O 3, that is biostatic (5) in nature. Theouter surface 160B of the pipe not exposed to water is shown. FIG.14A(1), lower diagram, depicts the side longitudinal cut-away view ofthe pipe in the upper diagram of FIG. 14A(1). The direction of the flowof water is indicated by arrow 162. The antifouling coating will preventthe development of mussels or barnacles within this pipe.

FIG. 14A(2), upper diagram, depicts a cross-sectional view of pipe 160coated with the anti-fouling coating comprising this invention, only nowthe polymer layers Polymer-I 9 and Polymer-O 3 are on the outside of thepipe 160B, as the pipe's outer surface 160B is now exposed to the water2 and the cyprid or veliger larval forms 165. Otherwise, the structuresdepicted are identical in all respects to that of FIG. 14A(1), upperdiagram. Likewise, the lower diagram of FIG. 14A(2) is the same in allrespects to that of the lower diagram of FIG. 14A(1) except for thebi-laminar polymer layer comprising Polymer-I 9 and Polymer-O 3 are onthe outside surface of the pipe, 160B. One-sided arrow 163 representsthe flow direction of some liquid or gas in the interior of the pipe 166with inside wall 160A which could also include water that is notinfested with barnacle or mussel larvae. Two-sided arrows 164 representother uses for the pipe, such as conductive cables being carried withinthe interior of the pipe. This embodiment is shown in both FIG. 20A,where it is depicted as being employed in a barnacle protected oceanwave energy converter and seawater electrolysis unit, and in FIG. 20B,where it is employed to protect a boat engine coolant system frombiofouling from barnacles or invasive mussels.

FIG. 14A(3), upper diagram, depicts a cross-sectional view of pipe 160,coated with the anti-fouling coating, only now the bilaminar polymercoating comprised of Polymer-I 9 and Polymer-O 3 coats both the innersurface 160A of pipe 160 as well as its outer surface 160B. In thiscase, the pipe carries water 2A containing cyprids or veligers 165within its interior and at the same time runs through a body of water 2Balso containing cyprids or veligers. Such a situation might occur withan intake water pipe lying at the bottom of a body of water drawingwater out of that body of water into a power or desalinization plant(for example pipe 231 in FIG. 20A). In this case, both the interior andexterior surfaces have to be protected from attachment and growth ofbarnacles and mussels. Larval forms 165 are seen both in the waterflowing through the interior of the pipe as well as in the watersurrounding the pipe. FIG. 14A(3), lower figure, shows the bilaminaranti-fouling coating in a longitudinal cut-away view showing both theinner and outer surface of the pipe protected from larva contaminatedwater. All structures in FIG. 14A(3) are the same as in FIG. 14A(1) andFIG. 14A(2) and perform the same function as described for FIG. 14A(1).Arrow 162 of FIG. 14A(3), lower figure, shows the direction of flow ofwater within the pipe with biofouling larval forms present. In thisembodiment pipe 160 is protected from fouling organisms on both itsinner and outer surfaces. This embodiment is shown depicted in FIG. 20A,where it is employed to protect both the interior and exterior of theseawater intake tube of the seawater electrolysis unit from barnaclesand growth of other organisms.

FIGS. 14B(1), (2), and (3) represent embodiments of the biofoulingprotected pipe that are similar to the application embodiments depictedin FIGS. 14A(1), (2), and (3), except that in this structuralembodiment, the pipe itself is a plastic polymer, such as polyvinylchloride (PVC) and itself is impregnated with biocides in the mannerdepicted in structural embodiments of FIGS. 1A, 5A, 5B,6A, 6B, 7, 8, and10A. The pipe itself becomes the inner biocidal Polymer-I layer and itsinner surface, outer surface, or both is coated with the biostatic outerPolymer-O layer. Note that the structural embodiment of FIG. 10B canalso be used with the outer Polymer-O layer containing biocidal biocidesonly for enhanced effectiveness in heavily contaminated water. Thebiocides are added to the plastic polymer pipe at the time ofmanufacture.

FIG. 14B(1), upper diagram, shows the plastic polymer pipe as 160 (alsolabeled as 9, the Polymer-I layer) with inner surface 160A and outersurface 160B with inner surface 160A coated by Polymer-O containing arelatively high concentration of biostatic biocide 5 and relatively lowconcentration of biocidal biocide 4. Plastic polymer pipe 160 isimpregnated with a relatively high concentration of biocidal biocide 4and relatively low concentration of biostatic biocide 5. Area 166represents the space around the pipe which could be air,non-contaminated water, soil, or some other medium. Contaminated water 2with floating veliger or cyprid larvae 165 is seen flowing in thedirection of arrow 162 labeled on FIG. 14B(1), lower diagram depicting alongitudinal cut-away view of the pipe, with the structures in thislower diagram labeled as per the upper diagram.

FIG. 14B(2) is a similar structural embodiment to FIG. 14B(1) only now,as depicted in the lower diagram, the Polymer-O 3 coating containing thesame biocide concentrations as before is covering the outer surface 160Bof plastic pipe 160. As before, Polymer-I 9 containing the same biocideconcentrations as before represents the same structure as plastic pipe160. Now contaminated water 2 with veligers or cyprids 165 is seenflowing outside of pipe 160 in no particular direction, while the insideof pipe 160 labeled as 166 might have uncontaminated water, anotherfluid, or a gas flowing in a direction represented by dotted arrow 163in FIG. 14B (2), lower diagram, depicting a longitudinal cut-away viewof the pipe, or electrical cables or other types of cables representedby double arrow 164 might be present. All other structures labeled inFIG. 14B(2) lower diagram are the same as in the upper diagram.

FIG. 14B(3) is a similar structural embodiment to the previous twostructural embodiments only that this embodiment combines the other twoin that now the outer biostatic Polymer-O coating 3 covers both theinner surface 160A and outer surface 160B of plastic polymer pipe 160,which is impregnated as before with the same biocides and biocideconcentration making pipe 160 again the Polymer-I 9. Contaminated water2 with veligers or cyprids is flowing in the direction of arrow 162(labeled on the lower figure depicting the pipe in longitudinal cut-awayview) in the interior of the pipe 160. In addition, there iscontaminated water 2 containing veliger or cyprids 165 that is flowingin no particular direction. Again all other structures in the lowerdiagram are labeled as in the upper diagram. In this particularembodiment, the pipe 160 is protected from fouling organisms on both itsinner and outer surfaces. The manufacture of the pipe must not involve astage requiring a temperature above the decomposition point of thebiocide that is incorporated within its polymer matrix.

Continuing with the application embodiments of the present invention,FIG. 15A depicts a cross-sectional view of a plastic pylon. Duringmanufacture, a plastic pylon 170 (9) is formed from a suitable plasticthat does not require a temperature in manufacture higher than thedecomposition point of the biocides that will be impregnated into thepylon and is impregnated with a biocidal biocide 4 and a lesser amountof biostatic biocide 5. Thus plastic pylon 170 also functions asPolymer-I 9. Pylon 170 is then covered with biostatic Polymer-O 3containing biostatic biocide 5 in high relative concentration andbiocidal biocide 4 in low relative concentration. Cyprid and larvalforms, including mussel veligers and barnacle cyprids 175, are seenfloating in the aquatic environment 2. This structure would find use inbiofouling structures such as piers, docks, bulkheads, platforms, pylonsfor off shore wind turbines such as structure 146 in FIG. 13C, bridges,causeways and so forth. The polymer in pylon 170 maybe made of any typewith sufficient mechanical strength and other physical properties tomake it useful to comprise the given structure that is needed.

FIG. 15B shows a longitudinal cut-away top view of a wall 175 that hasvarying sized three-dimensional plastic structural bricks or blocks 174(9) impregnated with biocidal biocide 4 in relative high concentrationand biostatic biocide 5 in relative low concentration at the time ofmanufacture. The interior of the brick functions as the biocidal portionof the coating, equivalent to Polymer-I 9 of the structural embodiments.Polymer-O 3 containing a high relative concentration of biostaticbiocide 5 and a low relative concentration of biocidal biocide 4 iscoated onto both sides of wall 174 (9) if the wall is surrounded bywater, and only one side if the wall is exposed to water on one side.Larval veliger and cyprid forms 175 are seen floating on both sides ofthe wall in the aquatic environment 2. The polymer in wall 174 may bemade of any type with sufficient mechanical strength and other physicalproperties to make it useful to comprise the given structure that isneeded. Appropriate structures that can make use of this embodimentinclude seawalls, light houses, oil platforms, buildings withfoundations exposed to bodies of water, locks, bulk heads, bridgepylons, and so forth.

FIG. 15C shows a longitudinal cut-way top view of a foundation 177 whosebottom rests on the seabed of a body of water 2 in which cyprid andveliger larval forms are floating. Barnacles and mussels are extremelydestructive to cement and concrete structures, causing them to crumble.The wall is comprised of porous cement 173 (9) and gravel 174 so thatthe structure is considered concrete. A liquid biocidal polymer,Polymer-I 9 is applied to the surfaces of the concrete foundation bypainting, rolling, spraying or some other means and is allowed to soakinto the outer layer of the concrete. The liquid biocidal polymer isimpregnated with a high relative concentration of biocidal biocide 4 anda low relative concentration of biostatic biocide 5. When cured and nolonger tacky, a second liquid biostatic polymer, Polymer-O 3 is appliedover Polymer-I and this polymer is impregnated with a high relativeconcentration of a biostatic biocide 5 and a low relative concentrationof a biocidal polymer 4.

The result of the sequential application of these two biocide-ladenpolymers is that the concrete structure and surface has been treated toresist barnacle and mussel implantation, growth, and proliferation. Thisconcrete anti-fouling coating and process is useful for the samestructures as listed for the biocide treated blocks and bricks in thedescription of the preceding embodiment in FIG. 15B. Note that concretestructure 177 would have to be treated while it was being poured andshielded from the sea water while it was setting, or once it was set, itcould be painted underwater with an appropriate polymer coating that canbe applied underwater.

In the latter case, Polymer-I 9 would not be a polymer that can beabsorbed into the concrete but would have to be painted on the surfaceof the concrete followed by Polymer-O 3. The concrete foundationstructure could be in addition to the immersed structures listed aboveFIG. 15B, as well as concrete boat launching platform ramps to keepthese structures free of barnacles or mussels.

If Concrete structure 177 is replaced by a wood structure such as ashipwreck, such a shipwreck which is always of valuable archeologicalvalue and suffers the greatest biofouling damage through the boring ofits wood by marine woodborers (shipworms, another calcareous calciumforming biofouling organism belonging to the same Mollusca phylum asinvasive mussel species), through the use of application of two layersof polymer coating suitable for underwater application such as underwater application epoxy polymer coatings and impregnated with thebiocides specified above, such threatened historical underwatermonuments can be saved from destruction.

Note if low viscosity fluoropolymers are used in both Polymer-I and thePolymer-O layer, then not only can the Polymer-I layer be allowed tosoak into the concrete first, but also the Polymer-O layer could next beallowed to soak into the concrete next to produce a concrete surfacewhose anti-fouling properties change gradually from biostatic at thesurface to biocidal deeper down within the concrete due to the changingcomposition of increasing concentrations of the biocidal biocide anddecreasing concentrations of the biostatic biocide with increasing depthof the concrete from the water surface.

As an extra benefit of this arrangement of polymers and biocides, theconcrete surface adjacent to the water will be completely waterproof.FIG. 15C shows a Polymer-O layer to be present both above and below theconcrete structure's surface which would be necessary if the structurewas in a vertical orientation completely surrounded by water. However,the bottom Polymer-O layer would be omitted if the concrete's bottomstructure rested horizontally on the sea floor.

An exemplary stretchable rubber polymer isethylene-propylene-diene-monomer (EPDM), a non-plastic rubber polymerthat is deformable, with a modulus of elongation of about 200% to about300%, which means it can be stretched 200 to 300% before it breaks. EPDMhas an operational life time in both freshwater and marine bodies ofwater of up to 25 years. For that reason it is used to waterproofrooftops, with a life expectancy of up to 50 years, and to line pondsand pools, with a life expectancy of operation of up to 25 years. Likefluoropolymers, this stretchable, flexible, non-plastic polymer is UVresistant. Its use allows extension of the properties and benefits ofthis invention to flexible and semi-rigid surfaces and structures. Anynon-plastic polymer possessing the mechanical, optical, and chemicalproperties of EPDM, especially of the synthetic rubber family, isuseable as a composition for the anti-fouling coating of this invention.Also, EPDM can be used as a Polymer-O layer topcoat on top of anothertype of polymer that is used in the Polymer-I layer bottom coat with orwithout a polymer primer depending upon the nature of the polymer in thePolymer-I layer.

FIG. 16A is an embodiment of the anti-fouling coating showing anextension spring coated with a bilaminar polymer coating whosecross-section is blown up in the adjacent inset drawing. Spring 181, isshown to be an extension spring, but which may be a compression springor any other type of spring, may be formed of an exemplary material suchas 17/7 stainless steel, noted for its tremendous resistance to metalfatigue, but any appropriate spring material may be selected including,e.g., stainless steel, spring steel, music wire, brass, titanium, and soforth, as well as plastics such as nylon.

Coated onto the spring is an inner biocidal layer of liquid EPDM 182 (9)that functions as a Polymer-I layer 9, impregnated with a relativelyhigh concentration of biocidal biocide and a relatively lowconcentration of biostatic biocide, upon which a second layer of liquidEPDM 183 (3) functioning as a Polymer-O layer 3 is coated and which isimpregnated with a relatively high concentration of a biostatic biocideand a relatively low concentration of a biocidal biocide. The spring mayextend and compress, and as long as the maximal extension of the springdoes not exceed about 200 to about 300% of its original length, the EPDMwill remain intact, affording anti-fouling protection to moving springssubmerged in water.

This is particularly valuable to wave energy converters producingelectricity from the mechanical motion of waves, such as illustrated inthe combined off-shore wind wave energy farm of FIGS. 13C and 20A, inwhich moving springs are often essential in transmitting the mechanicalenergy pulse from the wave and float into the rotor of the generator.Biofouling of a spring will render it inoperative in a short period oftime followed by rupture, and this described embodiment of the presentinvention is capable of preventing barnacles and invasive mussels fromattaching to springs, interfering with their movement, function, and thefunction of the equipment of which they are a part, and eventuallydestroying them as well as the equipment that they are a part of.

FIG. 16B depicts another embodiment of the anti-fouling coating showingan extensible cable, known as an anchor line, that can change its lengthwhen a tension force is applied to it and restores its original lengthwhen the tension force is removed. Also known as a bungee cord, a majoruse for such a structure is for anchoring leisure boats and allowing theboat to oscillate both horizontally and vertically with waves, tides,and currents. Such cables are useful if the boat is exposed to very badweather and large waves, preventing the mooring lines from being snappedand the boat being damaged. Most conventional extension cables rupturefrom various reasons—exposure to salt water, UV deterioration, barnaclesand mussels. Mussels have a particularly high predilection for cablesand woven fabric lines.

These structures are usually composed of a core of long stretchablerubber fiber lines that have none of the durable properties of EPDM,surrounded by a woven fabric of some type, usually nylon. They usuallycan double their length on stretching but never last more than oneseason before the rubber fiber lines snap or lose their stretchableproperty. They come in lengths up to several meters.

Another type of stretchable boating device for boat docking is thesnubber, usually made out of polyurethane rubber. A snubber is about 12″to about 24″ long and is capable of being stretched to about 1.5 timesits resting length. They are used to absorb the rocking motion of theboat that normally would otherwise cause significant friction of thedocking lines against the dock causing the lines eventually to fray andsnap.

The anchor line is usually very problematical with biofouling because itis always in the water and the anchor line cannot stretch with a largebiomass of mussels or barnacles attached, which often causes prematurerupture of the lines. Biofouling less of a problem with snubbers,because they are above the water line, but they can be contaminated withveligers in freshwater lakes and spread the invasive mussels. Theanti-fouling coating of the present invention allows the enablement of asignificant improvement in these structures.

The snubber is simply coated with the same two layers of biocideimpregnated EPDM Polymer-O layer 3 and Polymer-I layer 9 respectively aswas the case with the springs, and this embodiment is shown as FIG.16B(1) as snubber 186, with dock line tie holes 187A and 187B at eachend, with the dock end of the dock line (not shown) wrapped first aroundthe upper tie hole 187A, then around the central section 187C, and thenaround the lower tie hole 187B before proceeding to the boat. When therocking motion pulls the boat away from the dock, the snubber stretchesstretching the line wrapped around it, absorbing the rocking motion awayfrom the dock and decreasing its amplitude.

The stretchable anchor line 186 is shown in its stretched state in FIG.16B(2) and in its contracted state in FIG. 16B(3). Anchor line 186 iscoated with or impregnated with a bilaminar EPDM biocide-impregnatedcoating having outer biostatic EPDM polymer coating, Polymer-O 183(3),that covers an inner biocidal EPDM polymer coating, Polymer-O 182(9)containing the same biocide structural composition as the spring in FIG.16A. Anchor line 186 is composed of a stretchable woven fiber matrix185A and 185B.

FIG. 16B(2) shows the anchor line stretched by wave action or the tidalelevation as it is normally connected between the boat and the anchor,which is fixed in position at the seabed or riverbed. The woven fabricfiber strands 185A is stretched apart as compared to the woven fabricfibers 185B that are now significantly closer as the passage of the waveor the tidal elevation allows the restoring force of the stretched EPDMpolymer layers to restore the anchor line 186 to its passive restposition shown in FIG. 16B(3).

When the stretchable anchor line is in its stretched state in FIG.16B(2), the weavings of the woven fabric fibers are shown stretched andseparated as fibers 185A. When the anchor line is in its contractedresting state, the woven fabric fibers are shown closer together asfibers 185B. Hence the bilaminar EPDM layer not only provides theanti-fouling properties to the anchor line, but it acts like a stretchedspring that releases its energy as a restoring force to return theanchor line to its rest length. The fiber provides the tensile strengthto the line, and the anti-fouling bilaminar EPDM coating provides thestretching and restoring force to the anchor line. When the bungee cordor anchor line is in its stretched position, the space between thecrisscrossed fibers of the anchor line's core are expanded, and when theanchor line is in its rest relaxed state, the space between thecrisscrossed fibers of the anchor line's core is compressed.

The anchor line can be extended to at twice its rest length but safelyless than three times its rest length because of the presence of thebilaminar EPDM coating having an elongation modulus of about 200% toabout 300%. The Polymer-I EPDM layer fully saturates the inner wovenfiber network 185. Without its presence, while the inner woven fibernetwork can be stretched as a result of a wave, there would be norestoring force to bring the anchor line back to its rest state. Theanchor line can also be considered to be a combination of long rubberband and a rope, where the rubber band possesses the anti-foulingproperties that keep the anchor line from assembling a bio-mass ofbarnacles or mussels.

Furthermore, when the anchor line 186 is constructed in conformance withthe specifications of this invention, the central woven fiber networkcannot only be made out of typical rope fiber strands like polyethylene,polystyrene, or nylon, but it can also be made out of woven aramidefiber, high molecular weight polyethylene (HMWPE), carbon fiber,stainless steel fiber, and other extremely high tensile strengthmaterials giving these anchor “bungee” lines tremendous tensile strengthbefore breaking. This in turn allows these anchor lines to be quitelong, with a length up to many meters. The advantages to the leisureboating industry are significant and three-fold: biofouling of anchorlines is eliminated, the need to replace anchor lines yearly is alsoeliminated, and boats can be secured over wide ranges of changes inwater levels including what is observed in storm surges and hurricanes.

FIG. 17A depicts another application of the anti-fouling coating of thisinvention which is a generalization of the application of FIG. 16B thatgives any rope or cable, stretchable or not, anti-fouling properties.FIG. 17A(1) shows a twisted rope composed of strands of fiber of metal,aramide fiber, carbon fiber, or plastic such as nylon, polyethylene,polypropylene, or HMWPE as well as natural fiber like hemp, wool, orcotton, as well as natural polymers such as rubber that are twistedtogether to form a rope.

If they the rope is of a non-plastic material, as is depicted in FIG.17A(2) where in the inset picture, rope fiber strand 195A is covered andimpregnated first with an outer stretchable EPDM biostatic Polymer-Olayer 191 (3) if the rope is stretchable, or with a non-stretchablefluoropolymer polymer or other plastic polymer with a non-stretchablerope. In either case, the polymer of the Polymer-O layer is impregnatedwith a relatively high concentration of biostatic biocide and arelatively low concentration of biocidal biocide.

Polymer-O is covers a Polymer-I biocidal layer 190 (9) composed of astretchable EPDM biocidal layer if the rope is stretchable or with anon-stretchable fluoropolymer or other plastic polymer with anon-stretchable rope. In either case, Polymer-I is impregnated with arelatively high concentration of biocidal biocide and a relatively lowconcentration of biostatic polymer.

If the rope is stretchable, the rope fibers would have to be comprisedof a stretchable polymer such as a rubber polymer, or the rope fiberswould have to be woven in a crisscross manner as depicted in FIG. 16Ballowing such stretch with applied tension. The spacing between thecrisscrossed strands of the stretchable rope would alternately expandand contract, but this does not happen for a non-stretchable rope. FIG.17A(3) depicts another rope where the inner biocidal Polymer-I layer,labeled 194 (9), is the rope fiber itself. If the rope fiber is aplastic polymer, then at the time of manufacture, it can be impregnatedwith a relatively high concentration of biocidal biocide and arelatively low concentration of biostatic biocide. In turn it is coveredby a biostatic Polymer-O 193 (3) layer comprised of a stretchable rubberpolymer such as EPDM if the rope is stretchable or a non-stretchablefluoropolymer or other plastic polymer with a non-stretchable rope. Ineither case Polymer-O is impregnated with a high relative concentrationof biostatic biocide and a low relative concentration of biocidalbiocide.

Again if the rope is stretchable, the rope fibers' plastic polymer wouldhave to be stretchable or the rope fibers would have to be woven in acrisscross manner as depicted in FIG. 16B, allowing such stretch withapplied tension. It is clearly evident that such single-plastic polymerfibers, impregnated with biocides so that the fibers themselves arebiocidal to biofouling organisms, constitute the inner Polymer-I layerand can be coated with a biostatic outer polymer layer. If the fibersthemselves are not impregnated with biocides so that the fiber is coatedby both the inner biocidal Polymer-I and outer biostatic Polymer-Ocoatings, in either case, they can be woven into thin threads, which canin turn be woven into biofouling resistant fabrics and fine nettingmaterials or they can be woven into complex and thick ropes and cables,which in turn can be woven into coarse nets and other flexiblestructures.

In all of the present embodiments, any structure that has a dualfunction of also being a Polymer-O outer biostatic polymer anti-foulinglayer will be labeled with a second (3) label in addition to the primarystructure label, and any structure that has a dual function of alsobeing a Polymer-I inner biocidal polymer anti-fouling layer will belabeled with a second (9) label in addition to the primary structurelabel. It is also to be pointed out that the plastic polymer, such asthe preferred fluoropolymer including flourourethanes and FEVE andrelated fluoropolymers, as well as non-fluorinated plastic polymers, maybe interchanged with EPDM and similar stretchable and flexiblenon-plastic rubber polymers. It is also to be noted that the use of EPDMcoatings gives the anti-fouling coating an extended multiple yearoperating life that would be as long as 5 years and more probable inexcess of 10 years, which is similar to the extended operating lifeafforded to the anti-fouling coating of this invention by the use offluoropolymers such as flourourethanes, FEVE, and similar suchfluorinated compounds.

FIG. 17B depicts a lobster or crab trap 198 with a lobster 199A or crab199B contained within it. Trap 198 is coated with an inner Polymer-Ibiocidal polymer layer and an outer Polymer-O biostatic polymer layer aspreviously described for FIG. 17A. The combined bilaminar polymer layercomprising Polymer-I and Polymer-O is labeled as 198A. As in the case ofthe rope of FIG. 17A, if the lobster or crab trap 198, which isconsidered to be a rigid or semi-rigid structure with the possibility ofsome inherent flexibility in its structure, is comprised of plastic,that plastic can be impregnated with the biocides in a mixture so thatits composition is that for a Polymer-I layer, and thus the lobster orcrab trap itself with function as a biocidal Polymer-I layer.

Because structure 198 is either rigid or semi-rigid, any of the polymersmentioned in this disclosure, whether the polymer is stretchable such asthe preferred stretchable polymer EPDM or not such as the preferredfluorinated polymers, would be useful in the anti-fouling coating forthis structure specified by this invention. The present embodiments thusprevent damage to the traps from biofouling. Further, because crabs,lobsters, and shrimps are also crustaceans, it is important that themore potent biocidal biocides are water insoluble and contained withinthe inner biocidal layer so that these more potentially hazardousbiocides do not affect the lobsters or crabs within the traps, either bykilling them or by allowing these biocides to enter the human food chainwhen these crustaceans are eaten by humans.

The benefits of this application embodiment can be extended to the largepolygonal frame-like structures used in aquacultural fish farms, anothertype of submerged structure plagued by barnacle and mussel biofouling,of which the only practical solution was to have their frames paintedwith copper based paints or the frames made out of pure copper that arenot environmentally friendly to the fish inside the aquafarmingstructures and in the case of the pure copper, quite costly, or have theframes made out of cupro-nickel alloy which would again be quite costly.The netting strung around the frames that confine the fish inaquafarming structures can thereby also be given antifouling propertiesby this invention.

FIG. 17C extends the benefits of the anti-fouling coating of thisinvention just enumerated for lobster and crab traps to the submergedstructural surface known as fish nets. Fish net 196 is shown, and thisstructure is considered to be highly flexible and requires some degreeof being able to be stretched. It is shown coated with the samebilaminar anti-fouling coating of the current invention as described inFIGS. 17A and B. The fishnet can be made out of any of the fibers listedunder the structural application for anti-fouling coated rope describedin FIG. 17A. If the fishnet is composed of a plastic or non-plasticpolymer, the biocidal composition of Polymer-I can be impregnated intothe polymer comprising the fish net at the time of manufacture so thatthe fishnet itself becomes Polymer-I and would then have the biocidaland polymer composition of Polymer-O applied to the fishnet to completethe anti-fouling coating of this invention.

Since the stretching capability of a fishnet would not be needed to benearly as much as a stretchable rope or anchor line, any reasonablyflexible polymer, plastic or non-plastic, would be useable in thisapplication. In some cases, “fishnet”-like structures may be completelyrigid, such as intake grates and filters for power inlet pipes forpower, water, and desalinization plants, or for sea water intakestrainers on boats and ships to filter sea water for the vessel'splumbing and engine cooling system and such structures would findbenefit having the anti-fouling coating of the present invention appliedto them. Flexible polymer anti-fouling versions of the presentembodiments, however, would not be needed for these rigid porousstructures. This embodiment of the invention comprising fish nets withintrinsic antifouling properties would be most useful for largecommercially deployed fishnets with extended periods of biofoulingexposure and for aquaculture polygonal containment structures.

FIG. 17D (1)-(4) show additional modifications of cables, this timerigid cables, to protect such cable structures against deposition ofbiofouling organisms. FIG. 17D(1) depicts a cross-section of a singlemetal cable 260 (in a 1×1 woven configuration) covered by an innerbiocidal Polymer-I layer 9, which in turn is covered by an outerbiostatic Polymer-O layer 3.

FIG. 17D(2) depicts a cross-section of a cable whose internal metalstructure 261 is woven into a bundle of 19 single strand cables 261A,which is a standard 1×19 cable configuration, and this central wovenbundle of single strand cables is surrounded by and impregnated with aninner biocidal Polymer-I layer 9 which is in turn covered by an outerbiostatic Polymer-O layer 3.

FIG. 17D(3) depicts a cross-section of a cable whose internal metalstructure 262 is woven into a bundle of 7 sub-bundles 262B, each having7 metal strands 262A, a standard 7×7 cable configuration, and thiscentral woven bundle of single strand cables is surrounded by andimpregnated with an inner biocidal Polymer-I layer 9, which is in turncovered by an outer biostatic Polymer-O layer 3.

FIG. 17D(4) depicts a cross-section of a cable whose internal metalstructure 263 is woven into a bundle of 7 sub-bundles 263B, each having19 metal strands 263A, a standard 7×19 cable configuration, and thiscentral woven bundle is surrounded by and impregnated with an innerbiocidal Polymer-I layer 9, which is in turn covered by an outerbiostatic Polymer-O layer 3.

The biocidal biocides can be introduced into the polymer surrounding andinfiltrating the metal strands at the time of cable manufacture so thatthe inner biocidal Polymer-I layer is an integral part of the cablewhich is then subsequently coated with an outer Polymer-O coating asshown on FIG. 17D(2)-(4), or the cable can be manufactured, jacketed inand impregnated by a polymer without biocides, and then subsequentlycoated first with an inner biocidal Polymer-I layer and then coated withan outer biostatic Polymer-O layer.

Alternatively, the cable may be manufactured as is more customary as anuncoated metal cable, to which first a Polymer-I layer and then aPolymer-O layer may be applied. The stainless steel inner cable core canbe substituted with any other metal of high tensile strength. As arepresentative very common commercially available example of such acable is a polyvinyl chloride polymer (PVC) coated and impregnated 316stainless steel cable in a 7×7 or 7×19 configuration. This PVC coatingcan be impregnated with biocides to give it a biocidal nature at thetime of manufacture and then subsequently the cable is coated with anouter Polymer-O layer of a biostatic nature, or the PVC may not have anybiocides added to it at the time of manufacture, and a Polymer-I andthen a Polymer-O layer may then subsequently in turn coated onto thecable.

In any of these configurations, the outer cable surface will remain freeof barnacle or invasive mussel attachment by the outer Polymer-Obiostatic layer, and if an occasional biofouling organism manages toattach, as soon as the inner Polymer-I layer is breached, the organismwill be killed on contact maintaining the integrity of and the tensilestrength of the metal cable core itself. Another extremely usefulembodiment of such an anti-fouling cable would use a Primer-I zinc-richpolymer primer on the surface of a single strand or woven stainlesssteel cable, such as in FIGS. 17D(1) and 17D(2)-(4) respectively, ratherthan impregnating the steel cable core with the Polymer-I biocidallayer. Instead, the zinc rich polymer primer would permeate the steelcable core and would provide extreme adhesion for the inner Polymer-Ilayer placed on top of it, followed by the Polymer-O layer, to produce abiocide impregnated fouling protected coating and cable of extremestrength and durability. If the polymer of the Polymer-O and Polymer-Ilayers both were comprised of a low friction fluoropolymer such as PFTE,flourourethane, FEVE, silicone or other low friction polymer, one wouldhave a cable possessing extremely low frictional resistance, extremelylong term anti-fouling resistance, and if fluoropolymers are used, UVresistance and exceptional durability and protection from cable failureeven in sea water that can last many years

FIG. 17E shows yet another cable embodiment of the present invention.Depicted in cross-section is a typical undersea submarine cable used fortransmitting data signals via optical fibers (shown) or electricity viacopper or aluminum cables (not shown). When these cables travel alongthe ocean or a large deep lake floor, the distance beneath the water isso great that there is very little plankton at these levels because ofthe lack of sunlight and photosynthesis, and for that reason barnaclesand mussels that require plankton for nutrition are not seen at thesedepths. However, as these cables begin to come ashore, beginning atabout 500 feet for quagga mussels in fresh water and at lesser depthsfor barnacles in salt water and zebra mussels in freshwater, biofoulingof these cables endangers cable integrity, and loss of cable integrityhas catastrophic implications.

Starting from the center of the cable, optical fibers 287 (or electriccables), petroleum jelly barrier 286, copper or aluminum tube 285,polycarbonate tube 284, aluminum water barrier 283, stranded steel wires282, Mylar tape 281, and finally outer polyethylene sheathing 280(9) areshown. It is outer polyethylene sheathing 280(9) that can be impregnatedwith biocides at the time of manufacture to give this sheathing thecharacteristics of an inner biocidal Polymer-I coating representative ofthe current invention, which can then be coated with an outer biostaticPolymer-O coating 288(3).

Alternatively, outer polyethylene sheathing 280(9) can be placed ontothe surface of the cable in the conventional way without impregnatedbiocides, and then the Polymer-I layer 289(9) can be deposited on top ofthe polyethylene layer, and the Polymer-O layer 288(3) can be placed ontop of the Polymer-I layer as specified by this invention. The doublelabeling of polyethylene sheathing 280(9), inner Polymer-I layer 289(9),and outer Polymer-O layer 288(3) indicate the dual roles of thesestructures within the cable, both as structural components of the cable,as well as functional biocide impregnated layers composing the presentinvention coated onto the cable, with the designation (3) referring tothe outer bio static Polymer-O function of structure 288, and with thedesignation (9) referring to the biocidal Polymer-I function of eitherthe biocide impregnated polyethylene sheathing 280 if used, or the innerPolymer-I layer 289 that is used if the polyethylene sheathing is notimpregnated with biocides. In all of these possible configurations,attachment of biofouling organisms by the Polymer-O layer is againinhibited, and if a few do managed to attach, they are killed on contactupon piercing the boundary of the Polymer-I layer keeping the integrityof the undersea cable intact.

The use of the current invention for rigid “fish-net” like structurescan be extended even further to the enablement of special-purposefilters with anti-fouling properties. FIG. 18A extends the use of theanti-fouling coating of this invention to enable the construction ofanti-fouling filters as depicted cut-away side views of filter structure200A, showing a honeycombed biocide polymer coated lattice filter medianetwork 200C, and also of with filter structure 200B, showing alongitudinal slot-like biocide polymer-coated lattice filter network200D such as used in accordion-like filters.

Filters 200A and 200B are also shown in cross-sectional view as wellalong with an enlarged view of the coated filter matrix labeled as 200C,200D. 200C and 200D represent the filter matrix of the honeycomb filterand the longitudinal slot filter respectively that are coated with theinner biocidal Polymer-I 9 layer and the outer biostatic Polymer-O 3layer. The filter matrix substrate 201 in each case can be made up ofmatrix materials including ceramics, metal, plastics, cellulose andvarious forms of fiber and would be coated with a biocidal Polymer-I 9inner polymer that would coat the filter matrix elements and in turn, becoated with a biostatic Polymer-O 3 outer polymer layer according to thespecifications for the Polymer-I and Polymer-O layers delineatedrepeatedly to this point.

The filter is placed where it can easily be changed for simplemaintenance. While a filter without an anti-fouling mechanismincorporated within it may mechanically remove larvae from the waterpassing through, once lodged in the filter, within 3 weeks the barnaclesand mussels will have grown and quickly begin to biofoul the filter,eventually rendering it non-functional and clogging the fluid flowchannel that is being filtered. If the filter matrix is a polymer, itmay incorporate the biocides required for functioning as a Polymer-Ilayer which would be added at the time of manufacture and the filtermatrix would then only need to be coated with the Polymer-O layer.

FIG. 18B shows a variation of an anti-fouling filter that has atwo-component or two-stage filter, where the upper-stage half-section ofthe filter 208 (3), with biostatic filter matrix substrate 201A that haswater with veliger or cyprid larval forms flowing into it that isbiostatic in nature because its filter media matrix substrate 201A iscoated with a Polymer-O biostatic polymer layer 3 that has a highrelative concentration of biostatic biocide, capsaicin (CA) 203, and alow relative concentration of a biocidal biocide, ivermectin (IV) 202.Thus in effect the upper-stage filter half 208 (3) with filter matrixsubstrate 201A functions as the Polymer-O layer 3, and for that reasonit is double labelled.

Likewise, the lower-stage half-section of the filter 209 (9) with filtermatrix substrate 201B that has water without veliger or cyprid larvalforms that were either repelled from the filter because of attachmentinhibition in the upper biostatic half section of the filter, or killedand filtered out by the lower biocidal half section of the filter. Thelower-half portion of the filter 209 (9) is coated with a Polymer-Ibiocidal polymer layer 9 that has a high relative concentration ofbiocidal biocide, ivermectin (IV) 202, and a low relative concentrationof biostatic biocide, capsaicin (CA) 203. Thus in effect the lower-stagefilter half 209 (9), with filter matrix substrate 201B, functions as thePolymer-I layer 9, and for that reason it is double-labelled.

208A is the perforated upper boundary of upper half filter section 208(3), into which water with larval biofouling forms flow in the directionof arrow 206, 209A is the perforated lower boundary of lower half filtersection 209 (9) out of which water without larval biofoulings form flowin the direction of arrow 207, and 207A is the perforated boundarybetween upper filter section 208 (3) and lower filter section 209 (9).

This biofouling protected filter filters out larval forms by inhibitingattachment or killing them to prevent biofouling biomasses from formingon pipes downstream from the filter. It prevents larval forms fromspreading downstream to contaminate other bodies of water, especiallyimportant for quagga and zebra mussel infestations of lakes and rivers.The larval forms are either killed outright in the lower half of thefilter or gradually die in the upper half of the filter, and in anyevent the larvae never mature into adults, preserving the filteringability and greatly extending the filter's operating life. The filter iseasily replaceable, so that if the filter is eventually clogged withdead larval and juvenile invertebrate biofouling organisms, it can besimply replaced with an easy maintenance procedure instead of alaborious and expense periodic scraping of mussels or barnacles off thedownstream pipes of power, water, and desalinization plants on a largescale, and plumbing systems of boats and ships on a small scale.

FIG. 18C is the exact same biofouling filter with the addition of ananti-algaecide function to the upper half filter section 208 (3), forexample with a metal salt mixture of pyrithione (PY) 205. Capsaicin (CA)203 and ivermectin (IV) are present as previously. The filter is capableof filtering out one-cell, primitive algal organisms before they canalso proliferate. Although such organisms do not directly causecorrosive action on the downstream pipes, they encourage barnacles andmussels to settle by decreasing water flow velocity. Furthermore, largemasses of algae can certainly obstruct pipes downstream from the filter.It is highly advisable to use a large pore pre-filter upstream from themain filter, as will be shown in FIG. 20A, to intercept large mechanicalobjects, particulates, and algae plants to prevent the main filter fromgetting quickly clogged from such objects. The pre-filter is also easilyreplaced as needed, and it too should be coated with the biofoulingcoating of this invention as should any piping leading to the filter.

In recent years, zinc pyrithione, the ingredient in numerous humananti-dandruff shampoos, has been used as an anti-algaecide component inbottom anti-fouling paints for boats. It is highly water insoluble (12mg/L). The pyrithione moiety is not toxic to animal life, especiallywith the low water solubility and the inherent bio-specific lethalitylimited to plants, algae, fungi, and bacteria. The amount of zinc ionreleased, which is toxic to barnacles and mussels as well as to benignand beneficial life forms in the aquatic environment in the same mannerthat copper ions are, is very minimal. For that reason it cannot be usedas a biocide for mussels and barnacles or other calcareous biofoulingorganisms. However, the zinc pyrithione does leach out gradually,putting a limitation on how long the anti-algae effect is maintained,and gradually biofilms, bioslime, and algae over the course of severalyears will eventually begin to accumulate. For that reason it should bepresent in the biofouling coating in fairly high concentrations byweight, between 1 and 10% with a preferential range of 4 to 7%. Thisrequirement also applies for its inclusion into the outer Polymer-Ocoating of the current invention and applies to any appropriatepyrithione metal salt that may be used instead of zinc pyrithione.

The particles of the pyrithone salts should be as small as possible toincrease the total surface area of these particles. Nanoparticle sizedparticles would be most beneficial. Many metal salts of pyrithione havebeen prepared, including the most common, zinc, but also silver, barium,strontium, titanium, copper (also used for algae control), calcium, andmagnesium as well as others. The following process is provided to makethe particles as small as possible.

The object is to prepare a mixture of pyrithione metal salts byprecipitating them out of solution simultaneously. Of particularinterest is the mixture of barium pyrithione (water solubility of about77 mg per L) and zinc pyrithione (water solubility of about 12 mg per L)to which a small amount of silver pyrithione (water solubility of about37 per L) is optionally added for additional biocidal (as an algaecide,fungicide, or bactericide) effect. Normally, when one metal pyrithioneprecipitates out, the precipitated particle size is decreased bydecreasing the concentration of the metal soluble salt, agitating thesolution with mechanical mixing, or decreasing the time the developingpyrithione salt crystal has in contact with the precipitating solutionof sodium pyrithione. Solutions may be highly agitated with ultrasonicsound waves that produce high pressure cavitation bubbles that can breakapart the developing crystals of precipitating solutions. Sharptransition changes from warm to cold will accomplish the same effect.But most importantly, a means has been developed to produce smallermetal pyrithione crystals by exploiting the presence of pointsubstitutions of very large barium+2 ions for the very small zinc+2 ionsin the zinc pyrithione crystal lattice.

When this occurs, an off-center ion defect has been produced whichproduces a repulsive ion charge asymmetry, repelling neighboring ions inthe crystal lattice away. At the point where charge dislocations occur,a developing crystal is more likely to fracture and stop growing. Stressfractures are likely to occur where a low concentration of very largemetal atoms with large atomic and ionic crystal radii is precipitatedout into a crystal anion cation lattice at the same time that a morehighly concentrated metal atom, with a much smaller atomic and ioniccrystal radius, is precipitated out into the same crystalline lattice.The crystalline lattice fractures because of the charge distortionsproduced by the very large metal atom among the smaller surroundingmetal atoms.

Barium has the second largest atomic and crystal ionic radius of anyheavy or transitional metal (only cesium has a larger atomic radius) andzinc has the smallest atomic and crystal ionic radius of these twogroups of metal ions. Hence these two salts are used together to producevirtually the largest possible off-center ion crystal lattice defectpossible, thus allowing the crystal to more likely to fracture intosmaller pieces by disruption of their crystallization planes as theycrystallize during the precipitation process. Small quantities of silverpyrithione, with a similar effect to that of zinc because of the silveratom's similarly small size and atomic and crystal ionic radius, areoptionally added because small quantities of silver ions will especiallyenhance the algaecide effect.

The specially prepared mixed barium zinc silver (silver is optional) isproduced by the following process. One unit (e.g., 1 liter) of distilledwater is prepared. Additional distilled water to dilute 0.05 units ofpure 40% aqueous Na Pyrithione down to 0.4 units of 5% with solutionthree serial dilutions. A dilute 0.01 molar solution of 0.25 units ofapproximately 0.01 molar solution of AgF is prepared. The AgF solutionis placed into a flask and place it into an ultrasonic cleaner withwater. Alternatively, an ultrasonic sonicator probe is introduced intothe AgF.

With the ultrasound turned on, the 5% Na Pyrithione is slowly addedwhile the ultrasonic water cavitation process is being applied to theAgF solution. This is continued until no more precipitate of silverpyrithione forms. The ultrasonic sound is stopped and the supernatantfluid is filtered out. 50 g of BaCl₂ powder and 250 g of ZnCl₂ powderare added to make a solution that will not be supersaturated withrespect to the BaCl₂ to cause it to precipitate out. The silverpyrithione is added to the solution of BaCl₂ and ZnCl₂ and turn on theacoustical energy source. 0.1 units of 40% Na Pyrithione solution areprepared and place into a spray model with a nozzle. While stirringconstantly if using the ultrasound cleaner, or while using theultrasonic sonicator, keeping the spray nozzle close to the surface ofthe BaCl₂/ZnCl₂ solution, the 40% solution of Na Pyrithione is sprayedthrough a nozzle spray bottle with force onto the surface of the BaCl₂and continued until no further precipitate forms. The precipitate willcontain Zn Pyrithione and Ba Pyrithione in a molar ratio of 5 to 1 andAg Pyrithione will be in the precipitate in trace amounts. Thesupernatant fluid is poured off and filtered, the precipitate is allowedto dry, and then the precipitate is crushed with a motor and pestle. Anyenhancement of this process by a commercial process would be consideredto be within the scope of the current disclosure.

The filter application embodiment of the present invention can beextended further to filters employing activated carbon (AC) and graphenenano-platelets (GNP) as their filter matrix. Consistent with thedefinition of discrete molecular structures (monomers) arranged intorepeating one- and two- and three-dimensional long chain molecules asthe working definition of polymers, the three-dimensional, multi-layergraphite repeating hexagonal carbon structure (and its two dimensionalsingle layer analogue, the graphene repeating hexagonal carbonstructure) may be viewed as polymers as previously defined with respectto this invention.

These two substances may be considered to be special type of polymerswhere the repeating polymer unit is the 6 carbon hexagonal unit, hexene.In the case of activated carbon, that substance is equivalent to porousgraphite in 3 dimensions, and in the case of the graphenenano-platelets, that substance is equivalent to pieces of single layergraphite or graphene. Both have a huge desirable surface area to volumeratio, desirable for an adsorptive type of filter for chemicalsubstances, with the GNP capability exceeding that of AC, but bothhaving the capability of not only filtering particulate matter very welland also the ability to adsorb chemical compounds extremely efficiently.This allows filters with efficient anti-fouling properties to beconstructed.

Whereas in the usual surface polymer, a solid mixture or suspension ofthe biocide molecules is intercalated between the polymer molecularstructures and are mechanically held there in a cage by the longmolecules of polymers, with AC or GNP the biocide molecules are adsorbedinto the innumerable crevices making up the huge surface area of AC orGNP and are held there by Van De Waal's intermolecular electrostaticforces rather than the mechanical forces of more conventional polymersmolecular matrices. The effect regarding the biocide impregnated polymercoatings constituting the present invention is essentially the same inboth cases.

In the same manner as with filters using discrete filter matrixstructures can be structured with a two-layer arrangement, with thefirst, upper layer being biostatic and coated with polymers that havebiocides impregnated into them, and whose second lower layer is biocidaland coated with polymers that have biocides impregnated into them, thesame structural arrangement can be done with filters having AC or GNP orboth. A quantity of AC may be mixed with a relatively larger quantity ofbiocidal biocide particles and a relatively smaller quantity ofbiostatic biocide particles and then introduced into a container to forma first biocidal layer. Then a quantity of AC may be mixed with arelatively larger quantity of biostatic biocide particles and arelatively smaller quantity of biocidal biocide particles and then thatis introduced into a container to form a second biostatic layer on topof the first biocidal layer. Fluid flow is into the second or upperbiostatic layer, out of that layer, and into the first or lower biocidallayer, and then out of the filter.

It is also possible to introduce additional layers in such a manner ontop of the other two layers containing additional biocides, includingalgaecides. While these filters generally use AC, because they can belarge and AC is inexpensive as compared to GNP, the latter can be usedfor small-dimensioned filters with the advantage that the latter has aneven higher surface area than does AC. GNP can be added to the AC as amixture or the AC can be used alone. Cyprids and veliger biofoulinglarval forms get trapped in the first biocidal layer of the filter, butbecause of the biostatic layer inhibiting attachment, they get eithertrapped and die, move in random directions and die, or the few that makeit to the second biocidal layer of the filter, die. The water that comesout of the filter is decontaminated to the structures and bodies ofwater downstream.

FIG. 19A shows water containing larval forms 210A in the form ofveligers and cyprids flowing into the upper half 119A (3) of filter 119that contains AC, GNP, or a mixture of the two. Also mixed in with thefilter matrix is a high relative concentration of particles of capsaicinbiocide (CA) 214 and a low relative concentration of particles ofivermectin biocide (IV) 212 that was mixed and impregnated into andadsorbed onto the filter matrix prior to it being placed into thefilter.

The biocides are strongly adsorbed onto the AC filter matrix surface andit stays relatively permanently there. Thus the upper half of filter119A (3) is essentially functioning as the outer biostatic Polymer-O 3layer within the filter providing for the necessity of the doublelabelling. The microscopic larval forms 210A in the water, going intothe filter as shown by arrow 210, are inhibited from attaching to the ACfilter matrix because of the biocides, and they will either stay in thatpart of the filter adsorbed onto the filter and eventually die, or somewill make it through boundary 119C and get swept into the lower half andbiocidal part of the filter, where they will all die.

In the lower half of filter 119B (9), the filter matrix is again AC (orGNP, or a mixture of the two) that was previously was mixed andimpregnated with and adsorbed onto a high relative concentration ofparticles of ivermectin (IV) 212 and a low relative concentration ofparticles of capsaicin (CA) 214 and these two biocides which are againstrongly adsorbed to the filter matrix, where it remains essentiallypermanently, allowing the lower half of filter 119B to function asPolymer-I 9. The Polymer-I layer 9 is introduced first into thecontainer housing the filter comprised by structures 119A(3) and119B(9), followed by Polymer-O 3 being introduced into that containerabove the Polymer-I layer 9.

Particles of capsaicin and ivermectin are shown schematically beingattached by the process of adsorption to particles of AC 216 along theside of the diagram depicting the filter. Water flowing out of the lowerhalf of the filter 119B has been cleansed of larval forms and the wateris sterile with respect to calcium forming invertebrate biofoulingspecies. This antifouling filter performs at least two functions.Barnacle and mussel growth is prevented in vital structures downstreamfrom the filter such as water intake pipes and vents for power plants,water plants, and desalinization plants that would cause severemaintenance issues with such structures and the spread of biofoulingcontamination downstream is prevented. These filters, convenientlylocated, can be replaced simply and much more easily than scrapingshelled biofouling organisms off these structures. A large-boremechanical pre-filter, preferably coated with an antifouling coatingcomprising the present invention, should be placed upstream to filterout larger mechanical objects that could prematurely clog up the mainfilter. Filters such as this, placed on the plumbing and bilge chambersof boats and ships, will help prevent spread of mussels, especially bythe leisure boating industry.

FIG. 19B represents exactly the same AC filter (or GNP or a mixture ofthe two) application embodiment of the present invention as FIG. 19Aexcept that a second biocidal biocide, lufenuron (LU) 215, was added tothe ivermectin (IV) 212 and the capsaicin (CA) 214 to enhance thebiocidal killing feature of the lower half of the filter 119 (9) and asecond biostatic biocide, a pyrethrin type of compound 213 at abiostatic low concentration level, was added to enhance the biostaticbiocidal effect of the upper half of the filter 119B (3). AC particles216 are again shown with the biocides absorbed to their surfaces.

FIG. 19C depicts the same type of filter as was shown in FIGS. 19A and19B, but the filter is shown within a pipe 218 with water containinglarval forms 210A flowing into the filter indicated by arrow 210, butnone being found in the water flowing out 211. Instead of a secondbiostatic biocide, pyrethrin (PY) 213, an algaecide, zinc pyrithione(PN) 217 or the mixed metal pyrithione whose formulation was justdescribed, was added.

FIG. 20A represents the structural embodiment of a real world apparatusincluding a wave energy converter (WEC) electrical generator powering asea water electrolysis unit. Such an apparatus could never be functionalfor more than one year after deployment in the ocean withoutantifouling, because of barnacle fouling. Unlike a boat or a ship, thiskind of apparatus cannot simply be scraped clean of barnacles withoutdoing significant damage to the surface of the apparatus, and removingit from the ocean would be a far more formidable and lengthy task thandry-docking a boat for several days.

In depicting the generator 230 of FIG. 20A, which is structurallysimilar in part to the WEC depicted in FIG. 13C, the structures (labelswill have an asterisk) that must be protected from barnacles to allowfeasible operation of the apparatus are shown. These parts, also seen onFIG. 13C, include the linear electric generator itself 157A*, the buoyportion 148 of the WEC, the metal enclosure 152* of the generator, powertakeoff and transmission cable 150* (to which the coating applicationembodiment of FIG. 17A is applicable), sliding bearing surface 158*, andspring 154* (to which the coating application embodiment of FIG. 16A isapplicable). WEC ballast counter mass 157C* and heave plates 157D* werenot seen on FIG. 13C. All of these parts must be coated with theanti-fouling coating of the present invention.

Now moving onto the seawater electrolysis unit 242, the structures thatare required to be coated with the anti-fouling coating of the presentinvention are outlined in dotted lines and the antifouling coating islabeled 238 wherever it is applied on the electrolysis unit. Thesestructures include: seawater intake filter and inlet 239, water inletpipe 231 coated on the outside and the inside with the antifoulingcoating 238 in the manner of the application embodiment of FIG. 14A (3),the underneath surface of the electrolysis buoy floatation collar 237,the electrolysis cell metal chamber 243, and exit pipe 238A (in themanner of application embodiment of FIG. 14A (2)) which only needs theantifouling coating on the outside because its interior carries seawaterfrom which cyprid barnacle larvae forms were eliminated by anti-foulingfilter 240 including a Polymer-O biostatic first half of the filter 3,through which water enters with cyprid larvae and in which these larvaeare either inhibited from attaching, trapped within this portion of thefilter, or they make it through along with the water to the Polymer-Ibiocidal second half of the filter 9 where they are killed as in theapplication embodiment of this coating seen in FIG. 18B and otherfigures and the water output from the filter 240, now free of anycyprids, now is able to enter the electrolysis cell through pipe ortubing 238A coated on the outside by antifouling coating 238 without theproblem of cyprids entering the electrolysis chamber and biofouling itto a non-functional state.

A large pore pre-filter 232 is designed to filter out large particularmatter and floating algae plants with a collection chamber 233 in frontof it. Water exits filter 240 and larvae-free water is pumped by waterpump 233A into ingress hole 235 and out egress hole 244 of water pump233A. The possibility of barnacles rendering the water pumpnon-functional has been eliminated. Other structures on the electrolysisbuoy 242 include a removable lid 236A held on to water flow path cover236 by two latches 245 and a cleaning hole 232A adjacent to pre-filter232 that allows removal of debris before it gets to the anti-foulingfilter. Removal of removable lid 236A allows maintenance servicingaccess to the entire filtering chamber.

Sea water, which includes algae and barnacle cyprid larvae, is pumped inby water pump 233A through ingress hole 239, proceeds through intakepipe 231, and flows into filter chamber 233 through ingress hole 246.Heavy debris, including algae plants and so forth, are filtered bypre-filter 232 and debris piles up behind it, which can be periodicallybe cleaned out via hole 232A. All of these structures are coated with ananti-fouling coating 238.

Debris free water, but still contaminated by one-cell algae organismsand barnacle cyprids, flows next into another chamber where antifoulingfilter 240 is present. Water first flows into the first half of filter240, labeled as 3 consistent with the biostatic biocide action of aPolymer-O layer as previously described. Here the water is also subjectto algaecide treatment with an algaecide present in the Polymer-O 3first half of the filter. At this point the cyprids are inhibited fromattaching, so they either float aimlessly or get trapped in the firsthalf of the filter and eventually die since they cannot attach. Thosethat make it out through the boundary between the first half biostaticpart of the filter and into the biocidal second half of the filter 9consistent with the Polymer-I layer die on contact with the biocidalbiocides there. The filter 240 may include any filter of the types shownin FIG. 18A-C and FIG. 19A-C.

By the time the water leaves the anti-fouling filter, the water is ridof all biofouling organisms and the biofouling free water enters pump233A through inlet 235. Water is subsequently pumped out by pump 233Athrough outlet 244. This arrangement allows the pump to pump water freeof any organisms that can biofoul the pump, thereby maximizing thepump's life. Power for the pump comes from WEC 230 via cable 244. Thewater gets pumped into return plastic pipe or tube 238A, covered with anantifouling coating on the outside, and brings biofouling organism-freewater into the electrolysis unit 243, where the water is split intohydrogen and chlorine (or oxygen in one type of sea water electrolysisunit) by cathode 240 and anodes 241, powered by electricity from the WECsent to the electrolysis unit by cables 244.

Note that the anti-fouling filter and the pre-filter can easily bechanged out for new filters and the water filter chamber can be easilyvacuumed and cleaned of debris. Thus, this apparatus, in order to workproperly over extended periods of time in the ocean, uses variousembodiments of the anti-fouling coating comprising this inventionthroughout this apparatus, both for the WEC portion and the electrolysisunit portion.

FIG. 20B shows a raw water engine-cooling system for boats and ships.One of the most common causes of premature engine failure is biofoulingand clogging of the internal water path of such a cooling system. Suchfailures can be prevented by the features of this invention, andfollowing the water path will reveal the resulting benefits.

Water flows in through a sea strainer 247 coated with the anti-foulingcoating 238 comprising the present invention, through antifouling filter250 and first biostatic filter section 3 then through second biocidalfilter section 9, and then is pumped into intake valve 248 via waterinlet pipe 251. Next the water, now veliger- and cyprid-free, is pumpedinto the engine cooling system by water pump 249. From there it ispumped to the oil cooler 227, then to the exhaust manifolds 221 and 226,then to the cylinder heads 222 and 225, then to the intake manifold 224.

Part of the water goes to the overboard hot engine water exhaust pipes229 and back into the lake, river, or ocean. The rest of the waterleaves the engine area through outtake valve 223 where the thermostathousing (not shown) is located and through the cold engine water bypasspipe 228 to recirculate back to the water intake valve 248 to start thecycle again. Whatever portion of pipe is exposed to the externalenvironment and water is coated on the outside with the anti-foulingcoating 238. No biofouling occurs internally in the engine because ofthe removal of the larval cyprid or veliger organisms by intakeantifouling filter 250.

As a second safety precaution, the piping internal to the boatcomprising the engine cooling system can also be coated by theanti-fouling coating on the interior of the piping in case any larvalforms made it past filter 250. Such antifouling coating is indicated bydotted lines and it would lie on the inside surface of the pipinginternal to the engine (though on diagram for spatial reasons it isshown solely on the outside of the piping). It is not necessary to dothis for the part of the circulatory path where the water temperature isvery hot, such as the overboard engine exhaust water tubes 229 or themanifolds 221 and 226, and cylinder heads 222 and 225 or the intakemanifold 224, as the temperatures are far too high to allow barnaclesand mussels to grow here.

The net result of this is four-fold: 1) there is no biofouling in andaround the engine; 2) engine life is improved; 3) water contaminatedwith biofouling organisms goes into the boat engine plumbing and comesout cleansed of contamination; and 4) the oil heat cooler (heatexchanger), the most frequent target for barnacles and mussels leadingto the most frequent cause of heat exchanger failure and subsequentengine failure, is now protected from bio-corrosion that causesmechanical heat exchanger failure and biofouling which prevents properwater flow and heat exchange causing engine overheating failure.

Valuable and essential sources of biocides of beneficial use for thisinvention are the plant alkaloids. Although the main emphasis in thedisclosure has been on capsaicin as a preferred member of this class,the use of capsaicin is to be considered representative of a wide rangeof natural plant alkaloids that show anti-arthropod properties.Capsaicin, a preferred plant alkaloid and biocide for the purposes ofthis invention discussed already in great detail, has long been used inChinese herbal medicine, has been approved by the EnvironmentalProtection Agency as an insecticide, and is one of the very fewpesticides that have no known toxicity to beneficial aquatic lifeforms.Pyrethrum, the alkaloid extract of the chrysanthemum, an extract longused in Chinese herbal medicine, was also described in detail withrespect to its chemically synthesized related compounds, the pyrethrinsand pyrethroids and their use as biocides in this invention. Many ofthese compounds have not been studied to the extent that every physicalproperty such as the diffusion constant, D, or the release rateconstant, Kh, (using Higuchi Model notation) or the adsorptioncoefficient, KOC, are known. However, in general, virtually all of themare water insoluble, or nearly so, are characterized by large molecularvolumes and weights, would be impregnated in an extremely stable mannerinto polymers of low porosity (e, using the Higuchi Model notation), andthus would be expected to have a very low D, a very high KOC, and thusan extremely low Kh, and thus a very miniscule chemical leaching rateout of the polymer matrix into the surrounding aqueous environment, andthus duplicate the physical behavior of capsaicin. Furthermore, the modeof action of these compounds is generally to either hyperpolarize ordepolarize in an irreversible manner the cellular membranes of thecentral nervous system of the targeted organism, thereby paralyzing itand killing it.

The use of large molecule biocides also has two other very importantadvantages. First, the porosity of the outer biostatic polymer-O layer,e in the Higuchi Model, can be reduced by the intercalation of largemolecules into the pores between long polymer molecules, furtherreducing the e porosity factor even more thereby helping to reducefurther the chemical leaching rate. Second, it has been well describedthat biofouling due to barnacles, mussels, and other biofoulants isincreased when the microstructure of the protected surface showsincrease roughness, ridging, crevices, and pores (such a micro-reliefstructure decreases washing away, effects of predators, and overallmortality of the settled organisms). Thus, by filling in the pores ofthe polymer, the large molecules of the biocide make it more difficultfor the organisms to attach helping the outer biostatic repellingPolymer-O layer repel the organisms and prevent attachment.

Another example of the group of natural plant alkaloid anti-arthropodChinese herbal insecticides that would be beneficially useful for thepurposes of the present embodiments is the extract of the thunder godvine. In particular, it is noted that the extract of Triptergiumwilfordii (thunder god vine) contains multiple plant alkaloids withanti-arthropod properties. At least three of them are insecticides thathave been investigated for their biocidal properties—celastrol(tripterine), triptolide, and wilforine. Celastrol is a large molecule,C29H38O4 with a large molecular weight of 450.61 g/mol and a watersolubility of less than about 1 mg/L. Triptolide, another largemolecule, C20H24O6, with a large molecular weight of 360.41 g/mol and awater solubility of only 0.017 mg/L. Wilforine is a very large molecule,one of the largest natural non-protein, non-nucleic acid proteins foundin nature, C43H49NO18, with an molecular weight of 867.9 and a watersolubility that is unmeasurably low, much less than about 1 mg/L.Wilforine's mechanism of action is to inhibit irreversibly the cellularNa+- K+-ATPase membrane transport system, thus irreversibly depolarizingthe cell membrane and paralyzing the nervous system of the arthropod.

All 3 drugs are safe enough to have been used in human medicine, willtarget arthropods, do not have any chlorinated moieties in theirmolecules, and are available at low cost in large commercial quantities.Thus, this molecular anti-arthropod natural plant three-componentbiocide alkaloid is excellent for use for the purposes of the presentembodiments. As noted below, these compounds would be expected to alsopossess anti-fouling activity against invasive mussels as well.

The list of plant alkaloids and Chinese herbal extracts showinganti-arthropod activity that is useful for and part of this invention isa subset of all known members of this class of compounds. There are manyplant alkaloid extracts with that do not meet the specific criteria andrequirements of this invention and therefore are not useful for thepresent embodiments.

It is further to be noted that the scope of biocides applicable to thisinvention may be further enlarged using known taxonomic andphysiological relationships that extend between different taxonomicanimal groups. It is to be noted that barnacles are crustaceans, andcrustaceans are arthropods. Insects, mites (and sea lice), parasiticworms, arachnids, and multi-legged worm like creatures (centipedes,millipedes etc.) are all arthropods, and biocides developed against anyone class of arthropods have been shown or can be shown to be activeagainst any other class of arthropods, with allowance for differentdegrees of efficacy. Many experimental studies confirm thiscross-therapeutic phenomenon. Thus, any member of the class ofinsecticides listed in the table of FIG. 21A, mitocides listed in thetable of FIG. 21B, plant alkaloids possessing insecticide propertieslisted in the table of FIG. 21D, whose molecules possess the requiredmolecular structure, physical properties, and chemical propertiesdelineated in detail within this disclosure would fall under the scopeof this invention when they are used as biocides against barnacles inthe compositions so specified in this invention. This suitability as abiocide against barnacles would also extend to any member of the classof Chinese natural herbal insecticides possessing the necessary physicaland chemical properties stated above. Furthermore, invasive shrimp andcrab species, especially of the type noted to biofoul oil platforms,because they too are crustaceans, would be successful targets of anyarthropod biocides that are effective against barnacles.

Furthermore, it is seen that because the taxonomic relationship betweenbarnacles and invasive mussels and shipworms is so close, though theformer organism is a member of the animal phylum Arthropoda, and thelatter two types of organisms are members of the slightly more primitivephylum Mollusca, organisms of the two phyla possess so manyphysiological, chemical, structural, and cellular and especiallyneuronal cellular membrane processes in common that a biocide effectiveagainst barnacles will be effective against invasive mussels andshipworms, and a biocide effective against invasive mussels andshipworms will be effective against barnacles. This phenomenon has beenshown to be operative in almost all instances by the present and pastuse of available biocides against barnacles and invasive mussels. Thisphenomenon is also the basis of the statement that members of thedesired class of Chinese herbal insecticides possessing the desiredproperties described as being beneficial to this invention, and that areactive against insects, and therefore, would be active againstbarnacles, also would be active against invasive mussels. However, thisinvention is the first process that fully employs this phenomenon basedon known taxonomic biological principles and processes listed above togreatly enlarge the use of available biocides for anti-fouling purposesusing the process, structure, and compositions of the anti-foulingcoating defined and described in the present invention.

The use of biostatic herbicides with fungicide and bactericideproperties, such as the pyrithione metal salts, are of furthersignificance in terms of enhancement to the functioning of theanti-invertebrate biofouling of this invention. It is well known thatthe formation of a biofilm micro-fouling including bacteria, fungi, andone cell algae such as diatoms enhances the colonization of surfaces bythe macro-fouling organisms that are the principle focus of thisinvention. If one has a mass settlement of cyprid or veliger larvae on asurface toxic to them, the result will be a layer of dead juvenilebarnacles or mussels which have just completed metamorphosis uponattachment with their small shells, forming a neutral interlayer ofincrease micro-relief structure and roughness as well as shielding laterarriving larvae forms from being exposed to contact with the toxicsurface, both of which creates favorable conditions for development ofother barnacles and mussels upon the dead layer. The addition of anherbicide to the outer biostatic Polymer-O layer greatly helps tomitigate against that undesirable process, first by making the surfaceless hospital from the biofilm to the arriving larval forms, and thenhaving a fewer number of them having the need to be repelled from thesurface by the biostatic outer polymer layer.

Note that zinc oxide is also algaecidal but is not preferred for use asthe zinc oxide is converted to zinc oxychloride, which is the samemechanism as its anti-barnacle and mussel effect, and it is toxic to theaquatic environment much in the same way as copper based coatings are.On the other hand, zinc pyrithione exerts its phytotoxic and algaecidaleffect through the pyrithione moiety rather than the zinc moiety, withno environmental harm, a process that is safe enough for humans to useas a dandruff shampoo. Furthermore, zinc pyrithione is beneficially lesssoluble in water, about 12 mg/L as opposed to zinc oxide, about 16 mg/L(pure water, but considerably more in sea water because of conversion ofzinc oxide to zinc oxychloride by the chloride ions in the water).

Embodiments of the present invention have tested for theireffectiveness. Panels of fiberglass were placed in the water in thetemperate climate of New York and were coated with various biostatic andbiostatic biocides in the manner of the present embodiments. The outerbiostatic layer of the coating of some treated panels was alsoimpregnated with the algaecide, zinc pyrithione (ZPT). Each biostaticand biocidal biocide tested had a panel with and without the algaecide.The panels with the ZPT were more effective at inhibiting survivingbarnacles than the panels just with the biostatic and biocidal biocidesalone, owing to the fact that an algae coating would partially shieldthe barnacle larvae from the outer biostatic biocide polymer layer,allowing more of them to get a foothold.

Sea Grapes (Moluga manhattansis) and Golden Heart (Botryllus schlosseri)were found during the test. These organisms displayed such voraciousgrowth, many times more rapid then the barnacle populations, that on thepanels without the algaecide, the Sea Grapes within two weeks coated thepanels with a biomass weighing at least 25 kg and 3 inches thick on a 12inch by 24 inch fiberglass panel, almost causing the panel to crack andsplinter apart as well as potentially rupturing the suspending cables.The Golden Hearts grew somewhat less rapidly, but nevertheless formedthick circular colonies on the panels intermingled with the Sea Grapes.The barnacles that initially survived because of the algae layer on thenon-algaecide panels, were smothered and killed by these two moreaggressive organisms. However, on the panels that were treated with theZPT algaecide and the biostatic/biocidal biocides, there were nobarnacles, no Sea Grapes, and insignificant amounts of Golden Heart andalgae.

Tests thus showed not only a synergistic effect from the ZPT and thebiostatic/biocidal biocides against barnacle growth and formation due toalgae growth inhibition, but also showed a total eradication of the twotunicates. The magnitude of this effect during testing was unanticipatedgiven that, for both of these biofouling invading organisms, there wereno known practical treatment strategies that were both effective andsafe for the aquatic environment.

One mechanism for this effectiveness appears to be potentiation of thebiostatic and biocidal biocides by the ZPT. A second mechanism may bethat the presence of the animal biofouling biocides that are used withinthe scope of this invention also extends the biocidal activity of theZPT so that it includes lower-order invertebrate animal organisms. Bothmechanisms may be operative.

It is hypothesized that the highly efficient tunicate sexualreproductive mode of ova and sperm that result in egg and subsequentlarvae formation, settling, and attachment is interfered with by thecombination of the multiple biofouling invertebrate biocides employed inthe embodiments of this invention and the algaecide. The other, lessefficient, asexual methods of tunicate reproduction, including buddingand colony fragmentation, are incapable of compensating for thisinhibition of sexual tunicate reproduction. It has been noted that thepresence of zinc in a surface coating can inhibit the maturation ofeggs, and reproduction by egg formation is much more critical to thetunicate proliferation, short range settling, and distribution then itis to barnacles and invasive mussels that primarily rely on cypriad andveliger larvae, respectively. Note that zinc is a component of the ZPTmolecule. Thus, the embodiments of this invention that employ the use ofan algaecide that is a member of the group of zinc and other heavy metalpyrithione salts are not only more effective against barnacles, invasivemussels, and other calcareous biofoulers, but also they represent thefirst completely effective, practical, and environmentally safetreatment of the virulent non-calcareous tunicate biofoulers.

Both the biostatic and biocidal biologically active agents up to thispoint have comprised impregnations within the polymer coatings designedfor biofouling mitigation of surfaces submerged in either seawater orfreshwater involvement. These embodiments may employ two or more layersof polymer coatings that contain a wide variety of biologically activeagents, deployed in numerous combinations, to eliminate calcifyingbiofouling animal organisms such as invasive mussels, barnacles,invasive crayfish, shipworms, and calcifying bryozoans, as well asnon-calcificating biofouling animal organism that include tunicates andother ascidians, especially sea grapes (Mogulla manhattensis, otherwiseknown as Sea Squirts) and Golden Hearts (Botryllus schlosseri).

In all of these cases the biocides are active against the mobile larvalforms of these invading pests, or the juvenile early settling forms ifsome larvae manage to implant on the surface coating. While some coatingembodiments are contemplated for use in aquatic environments againstthese larval and juvenile forms, some of the biologically active agentsdescribed herein also have antiviral properties. These compounds mayexert their antiviral effects by killing on contact, or by preventingvirus attachment to living hosts. These properties can eradicate virusescirculating in non-aqueous moving fluids, such as air. Such virucidalmaterials include Ivermectin, cupronickel, metal pyrithione salts, and abiologically active agent not previously used in these embodiments,1,2,3,4,6-pentadigalloyl-glucose (PDG).

It has been found that heavy metal ions and atoms inhibit both theability of viruses to attach themselves to cells and their surfacereceptors by interfering with viral attachment proteins (for instancethe spike protein in coronavirus, and the hemagglutinin protein ininfluenza virus). In addition, they can kill the virus directly byinteracting with their lipid and glycoprotein envelope in the samemanner as soaps, alcohol hand sanitizers, ozone, hydrogen peroxide, andbleach. Hence the heavy metal ions of a heavy metal pyrithione caninhibit virus attachment and kill viruses by a direct toxic effect onthem. Likewise, the copper atoms of the cupronickel alloy used in thisdisclosure inhibit the virus in the same manner as the heavy metalpyrithione salts. Furthermore, the compound PDG facilitates attachmentof the heavy metal ions to the spike-shaped viral attachment proteins,thereby disrupting viral attachment and the integrity of the viruscapsule. Finally, Ivermectin has a direct killing effect on severalviruses. PDG also is a known astringent that is capable of denaturingthe attachment proteins of the virus, as well as the proteins that makeup the virus capsule enclosing the viral nucleic acids responsible forinfectivity.

The impregnation of these antiviral biocides within the filter medium ofan airflow filter, through which circulating air is pumped, will eitherremove and/or disinfect viral particles present in the circulatingairflow. If any viral particles make it through the filter on the firstpass, they will be removed and/or rendered non-contagious on subsequentpasses, with any remaining viruses not trapped within the filter beingrendered now non-contagious.

Thus, in some embodiments, instead of a polymer paint-like coating, thestructure may include a two layer filter, through which the workingcirculating fluid is air and not water. Whereas other embodiments mayuse water as a circulating fluid, with a variety of animal organisms inthe water, air may contain viral particles, which may be eradicated toprevent human infection.

Referring to FIGS. 18. A, B, and C, as well as FIGS. 18D and 18E, whichillustrate the antiviral functioning embodiments using US light andelectrostatic attraction working in conjunction with anti-viralbiologically active agents impregnating the filter medium, a firstfilter uses packed polymer filaments 200C as the filtering medium. InFIG. 18A, the first filter may packed polymer sheets of a filter medium200D as the filtering medium. Other structures, such as honeycombs,porous sheets, and so forth, may be used. The polymer filter medium maybe any appropriate filter medium, including cellulose, Nylon, polyester,polypropylene cloth used in N95 respirators, carbon fiber, and so forth.Packed polymer filaments 200C and packed polymer sheets may have apolymer coating that includes biologically active agents in the form ofbiostatic and biocidal biocides impregnating that coating. In someembodiments of a filter with antiviral activity using moving air as theworking fluid, the biocides may be deposited on the filter medium 100Cor 200D by coating, spraying, evaporation, vapor deposition, and soforth. It is also possible to impregnate the polymer filter mediumfilaments, sheets, and any other filter medium structure with thespecified biocides.

FIG. 18B shows a variation of antiviral filter 208 that has a twocomponent or two stage layered structure that includes layers 208(3) and209(9), analogous to the Polymer-O and Polymer-I layers described above,where the upper stage half-section of the filter 208(3) with biostaticfilter matrix substrate filaments 201A and 201B that has inward flowingairflow 206 that is pushed into the filter with either a fan or a pump.Filter medium 201A includes filament polymer filter medium 200C of FIG.18A, but the sheet polymer filter medium 200 D of FIG. 18A may be usedas well. Viral particles are shown, but not labeled, in FIG. 18B, andare labeled as 210A in FIGS. 19A, 19B, and 19C. Whereas elements 210Amay also represent larval veligers and cyprids, in a virucidal contextthey may also represent virus particles. Element 206 in FIGS. 18A and Brefers to the flowing fluid, for example water or air.

The upper half section 208(3), corresponding to the outer Polymer-Olayer, is biostatic in nature in that it will entrap viruses 210Amechanically and cause them to mechanically get ensnared on the filtermedium 201A. Once on the surface of the filter media, the active viruscan remain infective up to three days, depending on the virus, thetemperature, and the humidity. However, the viral particles will berendered inactive quickly by the antiviral biological agents, therebypreventing further future attachment infectivity on living cells byhindering the virus's attachment ability, which in turn will preventmultiplication of the virus within the cell. Ultimately the virus ceasesits existence.

This can be accomplished with the presence of a high concentration metalpyrithione salt (M_(P), labeled as 101 in FIG. 10A(4)) which isvirustatic. A relatively low concentration of an agent is included thatkills viruses on contact agent, such as cupronickel (C_(N), labeled 106on FIG. 10A(4)), which at such concentrations would be also virustatic,giving the upper half of the filter 108(3) an antiviral virustaticcharacter which will inhibit viral infectivity and viral attachment tohost cells.

The chemical PDG may be added, because it in itself aids the attachmentsof the metal ions and atoms to the virus, and also because it is anastringent, which can deform and denature the attachment proteins on thesurface of the virus, causing it to lose its infectiousness. Structure203 may thus represent capsaicin (C_(A)), as described above, or PPG forvirucidal embodiments.

Ivermectin (Iv) in this embodiment 202 will not appear in that upperouter Polymer-O layer 208(3), only in the lower inner Polymer-I layer209(9). A specifically contemplated concentration by weight of the metalpyrithione (M_(P)) salt is 1% of the weight of the filter medium, with auseable range of 0.1% to 5%, and a specifically contemplated preferredrange of cupronickel (C_(N)) is 1% of the weight of the filter medium,with a useable range of 0.1% to 5%. Nano-powder particles are used asthe virus particles are quite tiny, as small as 30 nm to 40 nm, and thesmaller the particle size, the better the metallic atoms and ions canattach to their attachment proteins. The concentration of PPG used byweight is 1% of the weight of the filter medium with a useable range of0.1% to 5%.

Airflow 206 next leaves the upper outer Polymer-O layer 208(3) of filter208, now with a decreased number of virus particles floating in it, withthe remaining still infectious virus particles, and it enters the lowerPolymer-I layer 209(9) of filter 208. The filter medium 201A in thisinner lower section of the filter contains a selection of antiviralbiocides and biologically active agents that are virucidal to theremaining virus particles. In this layer, impregnated onto the filtermedium, is a relatively high concentration of cupronickel nanoparticlepowder, with an exemplary concentration by weight of 5% of the filtermedium (with a useable range of 1% to 5%), and the biologically activeagent Ivermectin, which is virucidal to many types of viruses, in anexemplary concentration by weight of 5% of the filter medium (with auseable range of 1% to 5%). Also present is PDG, which, as explainedpreviously, in the upper half of the filter 208(3) aids in attachment ofthe metal ions of the metal pyrithione salt and the copper atoms andions of the cupronickel to the attachment proteins of the virus,rendering it non-infectious. PDF may be present in the same contemplated1% concentration by weight of the filter medium (with an exemplaryuseable range of 0.1% to 5%).

In this layer, the concentration of the metal atoms and ions are nowhigh enough to kill the virus as well through direct toxic effects onthe virus, and the Ivermectin (Iv) 202 that is also present in thislayer is directly toxic to the virus particles. The Polymer-I layermechanically entraps any virus particles present onto the filter mediumwhere they are exposed to the biologically active agents, and the virusparticles are rendered inactive. The airflow now leaves the lowerpolymer filter layer Polymer-I as airflow 207 back into the surroundingspace, only to re-circulate back into the filter through many serialcycles, thereby decontaminating the surrounding space completely ofinfectious virus particles. Note that FIG. 18C is another representationof the embodiment filter. In FIGS. 18B and 18C, Ivermectin (Iv) 202 isseen in both filter layers, but may be in only the inner lower layer invirucidal embodiments.

In FIGS. 18B and 18C, instead of capsaicin (C_(A)) 203 appearing in theupper outer layer (208)3, both a metal pyrithione salt (M_(P)) 102 ofFIG. 10A(4) and cupronickel (C_(N)) 106 of FIGS. 10A3 and 10A4 mayappear, and in the lower inner layer 209(9), cupronickel in asignificant higher concentration may appear along with the Ivermectin.Note that the embodiments of FIG. 10A(3) show the embodiment of using alower relative concentration of cupronickel (C_(N)) nano-powder 106 inthe outer upper Polymer-O layer and a higher relative concentration ofcupronickel (C_(N)) nano-powder 106 in the inner lower Polymer-I layerof the filter. In both layers, the PDG nanoparticles that facilitateattachment of the metal atoms and ions to the virus attachment proteinsare shown as structure 203, which may represent the PDG, rather thancapsaicin.

To disable a virus's attachment ability and proliferation ability, thevirus must be exposed to either the virustatic biocides, by settlingonto the outer upper Polymer-O layer, or, if the virus penetrated thatlayer, the virus must be exposed to the virucidal inner lower Polymer-Ilayer. In either case the virus attaches to the surface of the filtermedium to come in contact with the biologically active agents that wouldeither inactivate its attachment protein mechanism or disrupt its outerprotein envelope. To minimize the number of viruses that penetrate bothlayers, the mesh of the pores or holes of the filter should besufficiently small to remove most of the viral particles, and yet allowa sufficient airflow to allow the air in a confined area to circulatemultiple times within a reasonable amount of time. Each recirculation ofthe air will mechanically remove the viral particles from the air, wherethey can be deposited on the virucidal- and virustatic-laden filtermedium to quickly inactivate the virus.

Virus particles may be aerosolized as naked viral particles as small as20 nm, but often the virus particle is spread via larger droplets ofmucous, secondary to coughing or sneezing, and they are up to 1000 nm insize. If the pores of the filter are too large, the pores will allowmany viruses to pass through the filter. Such viruses may still beinfectious as they did not stay in reasonably long contact with thevirucidal biological agents on the filer medium. If the virus particlespass through the filter, they may settle on the surfaces located in thespace surrounding the filter, thereby allowing for human contaminationand spread of infection; these viruses can remain viable on surfaces forup to 3 days depending on the temperature, the humidity, and the natureof the surfaces.

On the other hand, if the filter pores are so small, the airflow will betoo low to virally disinfect the entire space. This problem can beremedied by the process of electrostatic particle attraction, to bedescribed below with reference to FIGS. 19D and 19E. The preferredmaterial for the polymer filter medium is the polypropylene cloth usedin N95 respiratory masks, which can remove up to 99.9% of particles from1000 nm to 20 nm in size, which includes naked aerosolized viralparticles as well as mucous droplets. Because of the multiple encountersof the viral particle with the filter medium rather than one passthrough a thin respirator cloth, such a filter described in thisembodiment as well as the next embodiment to be described, an activatedcarbon filter, will allow numerous encounters with the filter medium oneach air circulation pass and on multiple circulation passes.

The viral particles are mechanically removed by the of inertialimpaction of the particles onto the polymer filter medium and diffusionbouncing of the particles off each other and the filter medium. Once theviral particles are removed by impact on the filter medium, thevirucidal and virustatic biological agents impregnating the polymerfilter medium inactivate the virus by the multiple mechanisms justdescribed. One can also add a high intensity UV light source, in theform of a UV bulb or LED, that illuminates the surface of the polymerfilter medium to assist the killing of the virus particles, as UV lightis virucidal to viruses. The UV light source is not shown in FIGS. 18Band C as an integral part of the filter, but it is shown in FIGS. 19Dand 19E, and it would be installed within the same canister as thefilter cartridge, as indicated in those figures. It is important to notethat if only mechanical removal of the virus were employed, without theuse of the biologically active antiviral agents, while some of the virusparticles would eventually become non-infectious after several days,some of them would remain, infectious creating a biohazard duringdisposal of such spent filter cartridges. Furthermore, the percentage ofviral inactivation would be much lower without the use of antiviralbiologically active agents.

However, a method can be employed to increase the efficiency of themechanical impact of the virus particle onto the filter medium, tofacilitate contact with the impregnated antiviral biocides on the filtermedium. If the viral particles are given an electrostatic charge,usually for example by the deposition of electrons upon them, they wouldbe attracted to a surface. This is the principle of the electrostaticair purifier. Virus-laden air passes through such an air purifier, isgiven a negative electric charge, and, when pushed out of the filter,the viral particles are eliminated from the cleaned air, as they areattracted to the relatively positively charged surfaces in theenclosure, being decontaminated by the filter. One challenge with thatprocess is that, while it removes the viral particles from the air, itmerely allows the facilitated deposition of the virus particles that arestill active and infective onto all the surfaces of the enclosed spaces,as the electric charge on the viruses cause them to be stronglyattracted by coulomb electrostatic forces to any nearby surfaces. Thepresent antiviral filter embodiments, however, eliminate this problem.The antiviral filter embodiments allow for the electric negative chargesto be placed directly on the filter medium impregnated with theantiviral biologically active agents, so that the filter medium itselftakes on a negative charge, and this negative charge, because of coulombattractive forces that now occur between the filter medium and the viralparticles, electrostatically propels the viral particles into amechanical collision with the filter medium thereby causing theseviruses to embed themselves into the filter medium, where they areinactivated by the antiviral compounds.

This process not only inactivates the viruses with increased efficiency,but also removes the viruses from the air circulating through the filterwith increased efficiency, producing a lower viral particle count inoutward airflows 207 and 211, thereby lessening the number ofrecirculating cycles needed to completely sterilize the enclosed spaceof viruses. The negative electrostatic charge is easily applied to thefilter from a high-voltage negative ion generator, as shown in FIGS. 19Dand 19E that, like the UV light source, can be placed within the body ofthe filter. Note that both the UV and electrostatic processes can beused together, synergistically enhancing viral inactivation and viralremoval by the antiviral filter. Both the UV light source and thenegative ion generator can be placed in close proximity to the filtermedium within the filter case to accomplish this enhanced virus removaland inactivation.

Referring now to FIG. 19D, an embodiment is shown that corresponds toFIG. 18B, with UV light and electrostatic enhancement that functions inthe manner just described. Filter 208 may include upper Polymer-Ovirustatic layer 208(3) and lower Polymer-I virucidal layer 209(9) andboundaries of these layers, 207A, 208A, and 209A. In upper layer 208(3),three biological active anti-viral agents can be used: metal pyrithione(now labeled as 202 and also labeled as 203A), which is virustatic, arelatively low concentration of cupro-nickel 203B, which is virustatic,and PDG 203 (tiny black particles as shown at end of arrow and on filtermedium filaments 201A and 201B) which is virucidal. All three of theseanti-viral agents make the upper layer virustatic overall, by inhibitingthe ability of a virus to bind to a human cell if and when it contactssuch a cell, which will result in the eventual death of the virus.

In the lower layer 209(9), there may be three biological activeanti-viral agents: Ivermectin 202A, which is virucidal, a relative highconcentration of cupronickel 203B, which is virucidal, in contrast tothe relatively low concentration of cupronickel in the upper layer,which is virustatic. Both of these agents inhibit viral multiplicationand will cause death of the virus quickly; PPG 203 may also be presentin the lower layer and is also virucidal. All three of these virucidalagents will make the lower layer virucidal overall in nature, which willkill the virus while it still is within the filter if it has impactedonto the filter medium.

Inward airflow 206 carrying virus particles 210A sweep the viruses intothe filter, first through boundary 208A, then through the upper layer208(3), then through interface 207A, then into the lower layer 209(9),then out of the filter through interface 209A as outward flowing aircurrent 207, now depleted of the great majority of viruses trapped infilter medium filaments 201B. As the viruses travel into, through, andout of the filter, they are either radiated by UV light from highintensity UV LED 405, that by emitting high energy UV photons 406 willkill some of the virus particles outright, or viral particles can begiven a static negative electric charge by negative ion generator 402,which will cause the viruses to impact upon filter medium 201A or 201Bcontaining the viricides. This allows virus particles that might besmaller than the pore size of filter medium 201A or 201B to still betrapped and removed from the air, obviating the need for such small poresize that air flow through the filter is compromised.

Either UV LED 405 or negative ion generator 402 may be employed in theoperation of the filter. For even greater efficiency of viral removaland killing, both devices may be installed within the filter inside themetal or plastic canister or container 407 that encloses filter 208. Thehigh voltage negative electrostatic charge is delivered through negativeterminal and wire 401 to negative terminal 400, inserted into filtermedium 201B of upper Polymer-O layer 208(3), and is indicated by theground figure. Any voltage of between 500 and 15000 volts, dependingupon the size of the filter cartridge, would be suitable. The electronsreturn to complete the electrical circuit via the positively chargedelectrode and wire 403, connected between filter 208 and the negativeion generator. If the canister's case is metal, the connection can bemade to the case, otherwise it has to be inserted into the filter medium201B of lower Polymer-I layer 209(9). Wire 401, if filter 208 isrelatively small, can be optional with the excess negative chargeeventually dissipating to the atmosphere.

Another embodiment of the two-layer Polymer-O outer polymer layer andPolymer-I inner polymer layer filter is depicted in FIGS. 19A, B, and C.In this filter, inward air flow 210, laden with viral particles 210A,enters the outer or upper (depending on vertical or horizontalorientation) Polymer-O 119A(3), and exits out of the inner or lower(depending on vertical or horizontal orientation) Polymer-I layer asoutward air flow 211 free of viral particles 210A. In these filterembodiments, the filter medium may be carbon polymers in the form ofactivated charcoal (AC) or graphene nanoplatelets (GNP) particles, whichadsorb the virustatic and virucidal biologically active agents onto thesurface of the particles that are bound through hydrogen bonding andother surface acting forces. The biologically active agents shown inFIGS. 19A, B, and C, with the exception of the Ivermectin (Iv) 212, maybe replaced by the three virucidal and virustatic biologically activeagents mentioned in the prior sheet or filament polymer filterembodiment, cupronickel nano-powder, metal pyrithione salt nano-powder,and PDG. The Ivermectin (Iv)) 212 is now found only in the inner orlower Polymer-I layer. The AC or GNP particles are shown as 216. In thisfilter embodiment, the Ivermectin adsorbed particles may be found onlyin the lower layer 119B(9), at a specifically contemplated concentrationof 5% (with an exemplary functional range of 5 to 15%) by weight of thecarbon filter polymer matrix. If we look at FIG. 19B, in the upper outerPolymer-O layer 119A(3), capsaicin (C_(A)) 214 may be substituted in thepresent embodiment by a metal pyrithione salt nano-powder (M_(P),labeled as 101 in FIG. 10A(4)), at a specifically contemplatedconcentration by weight of 5% of the carbon polymer filter medium (withan exemplary suitable range of 5% to 15%), the pyrethrum (P_(Y)) 213 inthe upper outer Polymer-O layer 119(3) may be substituted by thecupronickel nano-powder (C_(N), labeled 106 on FIG. 10A(4)) in aspecifically contemplated of a preferred 2% by weight of the carbonpolymer filter medium (with an exemplary suitable range of 1 to 5%), andin the lower inner Polymer-I layer 119(B), the Lufenuron (L_(U)) 215 ofFIGS. 19B and 19C may be substituted by the cupronickel nano-particlesin a relative higher concentration of a specifically contemplated 5% byweight of the carbon polymer filter medium (with an exemplary suitablerange of 5% to 10%).

The PDG, not shown in FIGS. 19 A, B, and C, but shown as particles 203in FIGS. 19D and 19E, may be present in both the upper or outerPolymer-O layer and the lower or inner Polymer-I layer. Air flow 206,after flowing through upper or outer Polymer-O layer 119A(3), flows intolower or inner Polymer-I layer, and then flows out of the filter asairflow 211. From there the air recirculates in the surrounding space tore-enter again the filter structure to repeat the process. Because ofthe granular nature of the filter medium of the AC or GNP type offilter, the biologically active agents can be employed in higherconcentrations by weight with respect to that type of polymer filtermedium then the filters that were described employing filament orsheeting type of polymer filters. This is because adsorbing particles216 can be impregnated with much higher concentrations by weight thancan the filament filter medium 200C or sheet filter medium 200D of FIG.18A.

Referring now to FIG. 19E, an embodiment is shown, relating to theembodiment of FIG. 19A, where UV light and electrostatic enhancementsare included, which function in the manner previously described for thefilament filter medium filter. Filter 119 includes upper Polymer-Ovirustatic layer 119A(3) and lower Polymer-I virucidal layer 119B(9) andboundaries of these layers, 119A, 119B, and 119C. In upper layer 119A(3)there may be three biological active anti-viral agents: metal pyrithione202, which is virustatic, a relatively low concentration of cupro-nickel203B which is virustatic, and PDG 203, which is virucidal. All three ofthese anti-viral agents in combination make the upper layer virustaticoverall in nature, by inhibiting the ability of a virus to bind to ahuman cell if and when it contacts such a cell, which will result in theeventual death of the virus.

In the lower layer 119B(9), there may be three biologically activevirucidal anti-viral agents: Ivermectin 202A; a relatively highconcentration of cupronickel 203B, which is in contrast to the relativelow concentration of cupronickel in the upper layer, which isvirustatic; and PDG 203. All three of these virucidal agents will makethe lower layer virucidal overall in nature, which will kill the virusquickly, while it is still within the filter if it has impacted onto thefilter medium, and will inhibit future viral multiplication by causingthe death of the virus quickly.

Inward airflow 210, carrying virus particles 206, sweeps the virusesinto the filter, first through interface 119A, then into the upper layer119A(3), then through interface 119C, then into the lower layer 119B(9),then out of the filter through interface 119B as outward flowing aircurrent 211, now depleted of the great majority of viruses trapped infilter medium carbon polymer particles 201B. As the viruses travel into,though, and out of the filter, they are either radiated by UV light fromhigh intensity UV LED 405 that, by emitting high energy UV photons 406,will kill some of the virus particles outright, or they can be given astatic negative electric charge by negative ion generator 402, whichwill cause the viruses to impact upon filter medium 201B containing theviricides. This allows virus particles that might be smaller than thepore size of filter medium 201B to still be trapped and removed from theair obviating the need for such small pore size that air flow throughthe filter is compromised.

Either UV LED 405 or negative ion generator 402 may be employed in theoperation of the filter. For even greater efficiency of viral removaland killing, both devices may be installed within the filter inside themetal or plastic canister or container 407 that encloses filter 119. Thehigh voltage negative electrostatic charge is delivered through negativeterminal, and wire 401 to negative terminal 400 is inserted into filtermedium 201B of upper Polymer-O layer 119A(3) and is indicated by theground figure. Any voltage of between 500 and 15000 volts, dependingupon the size of the filter cartridge, would be suitable. The electronsreturn to complete the electrical circuit via the positively chargedelectrode and wire 403 connected between filter canister 119 and thenegative ion generator. If the canister's case is metal, the connectioncan be made to the case, otherwise it may be inserted into the filtermedium 201B located within lower Polymer-I layer 119B(9). Wire 401, iffilter (filter cartridge) 119 is relatively small, can be optional withthe excess negative charge eventually dissipating to the atmosphere.

The fact that carbon polymer filter medium particles 201B are activatedcharcoal and graphene nanoplatelets particles are made of pure carbongives them an enhanced electrical conducting and charge storage capacitythat enhances the electrostatic attraction of the virus particles thatare positively charged relative to the negatively charged filter medium,and the fact that these particles are of such vast surface area, with atiny branching dendritic structure producing a very complex set of tinyinterlocking pores, and that viruses are held within the pores of theseparticles by Van Der Waals and London intermolecular electrostaticforces, all contribute to making the embodiment of FIG. 19E, of a twolayer carbon polymer particle filter, more efficient than that of theembodiment of FIG. 19D of a two layer filament or sheet polymer filter,in inactivating, removing, and killing of viruses present in thecirculating air current through the filter. This results in a reductionof the number of circulations needed to completely disinfect an enclosedspace in which the filter is located.

Research so far has indicated that these four biologically active agentsare antiviral in character, and that is the basis for theirincorporation into these filter embodiments employed as antiviralfilters. However, any of the numerous biologically active agents thatare suitable for water-submerged anti-fouling coatings that are found tohave antiviral properties would be suitable for use in these antiviralfilter embodiments. It would be obvious to those who are expert in theart that these substitutions can lead to a wide variety of additionalembodiment arrangements, using a different selection of antiviralbiologically active agents, some of which may be expected to haveincreased effectiveness over the current embodiments.

Furthermore, since now the fluid carrying the biological invadingagents, in this case viruses, may be air rather than water, lowsolubility for the biologically active agents is not needed. This factis what allows the use of PDG, which is highly soluble in water, to beused in these filter embodiments to potentiate the antiviral effects ofthe specified biologically active antiviral compounds. As new, highlywater soluble biologically active agents are found to possess antiviralactivity, these substances too can used to generate further variationsof these filter embodiments that may have enhanced effectiveness asantiviral filter agents. Finally, in addition to the metal pyrithionesalts that are used in the outer Polymer-O layer, any heavy metallicsalt that is stable under ordinary atmospheric temperature and humidityconditions may be substituted in these antiviral filter environments.Likewise, the cupronickel nano-powder may be substituted with heavymetal powders consisting of pure metals like zinc, silver, iron,titanium, copper, strontium, just to name some appropriaterepresentatives of the group of heavy metals, either in their singlemetal pure form, or in metal alloys in which they are ingredients thatwill allow additional embodiments of these anti-viral filters to beconstructed.

If some of these metal salts that are naturally mildly hygroscopic innature are used to keep the interior of the filter in a high humidifiedstate, virus control can be further enhanced, as the layer of moistureis inhibitory to many viruses, including coronavirus and influenzavirus. The layer of moisture facilitates both the mechanical contact ofthe virus to the filter medium and will also facilitate the chemicalanti-viral reactions between the anti-viral biologically active agentsand the glycolipid and glycoprotein viral envelope, as well as itssurface attachment proteins. For instance, the combination of zincpyrithione and zinc chloride (ZnCl₂) is particularly efficacious, and isonly one of a myriad number of such embodiments.

The representative metal pyrithione, when mixed with a with a smallquantity of this antiviral salt, ZnCl₂, that is also both hygroscopicand in very high humidity deliquescent, with the amount of ZnCl₂ addedbeing such that the filter medium always remains just slightly moist,provides an excellent representation of the use of such a method ofmoisture and humidity enhancement of viral deactivation by the twolayered anti-viral filters described herein. Virtually all zinc saltsare anti-viral, as are most heavy metal salts, and there are numerousexamples of these salts being both hygroscopic and deliquescent, sothere are a vast number of combinations employing metal pyrithione saltsand other heavy metal hygroscopic and deliquescent salts that canfacilitate the moisture enhancement process to potentiate the effects ofthe anti-viral biologically active agents used in these filterembodiments and filter systems.

Those skilled in the art would be able to determine other suchembodiments that would all still fall under the art represented by thecurrent invention. Likewise, the theoretical number of applicationembodiments encompassing various yet to be determined applications ofthis invention in the field of biofouling prevention, when they would inthe future become apparent to those skilled in the art that encompassesthis invention, would be expected to be large, but this broad universeof applications would be embodiments that would fall within the scope ofthe current invention.

The foregoing is to be understood as being in every respect illustrativeand exemplary, but not restrictive, and the scope of the inventiondisclosed herein is not to be determined from the Detailed Description,but rather from the claims as interpreted according to the full breadthpermitted by the patent laws. Additional information is provided inAppendix A to the application. It is to be understood that theembodiments shown and described herein are only illustrative of theprinciples of the present invention and that those skilled in the artmay implement various modifications without departing from the scope andspirit of the invention. Those skilled in the art could implementvarious other feature combinations without departing from the scope andspirit of the invention.

What is claimed is:
 1. A method of protecting a submerged surface frombiofouling animal organisms, comprising: applying a first biologicallyactive inner polymer layer on a surface, impregnated with at least onefirst biologically active agent that kills a juvenile stage of abiofouling animal organism; and applying a second biologically activeouter polymer layer on the first biologically active inner polymerlayer, impregnated with at least one second biologically active agentthat inhibits a larval stage of the biofouling animal organism fromattaching to the second biologically active outer polymer layer, whereinthe second biologically active outer polymer layer comprises afriction-reducing additive selected from the group consisting ofsilicone powder, PTFE powder, molybdenum disulfide powder, graphenenano-platelets, graphene oxide, and fluorinated graphene powder.
 2. Themethod of claim 1, further comprising applying a first biologicallyactive primer layer on the surface before applying the firstbiologically active inner polymer layer to enhance adhesion of the firstbiologically active inner polymer layer to the surface.
 3. The method ofclaim 2, wherein the first biologically active primer layer comprisesone or more agents that are lethal to the juvenile stage of thebiofouling animal organism.
 4. The method of claim 1, further comprisingapplying a second biologically active primer layer on the firstbiologically active inner polymer layer after applying the firstbiologically active inner polymer layer and before applying the secondbiologically active outer polymer layer to enhance adhesion of thesecond biologically active outer polymer layer to the first biologicallyactive inner polymer layer.
 5. The method of claim 4, wherein the secondbiologically active primer layer comprises one or more agents selectedfrom the group consisting of agents that inhibit the larval stage of thebiofouling animal organism and agents that are lethal to the juvenilestage of the biofouling animal organism.
 6. The method of claim 1,wherein the first biologically active inner layer further comprises anagent that inhibits the larval stage of the biofouling animal organismin a concentration below a concentration of the first biologicallyactive agent in the first biologically active inner polymer layer andwherein the second biologically active outer layer further comprises anagent that kills the juvenile stage of the biofouling animal organism ina concentration below a concentration of the second biologically activeagent in the second biologically active outer layer.
 7. The method ofclaim 1, further comprising applying a sheet of perforated material tothe first biologically active inner layer before applying the secondbiologically active outer layer to provide structural support andstiffness, where the first biologically active inner layer and thesecond biologically active outer layer are each formed from multiplerespective coatings at different concentrations of the respectivebiologically active agents in each layer.
 8. The method of claim 1,wherein the first biologically active inner polymer layer furthercomprises an adhesion- and durability-enhancing additive selected fromthe group consisting of aramide fiber, fluorspar, boron carbide, cubicboron nitride, silicon carbide, carborundum, metal carbides, sand, andindustrial diamond.
 9. The method of claim 1, wherein the secondbiologically active outer layer further comprises an agent that includesone or more metal salts of pyrithione in the form of nano-sizedparticles.
 10. The method of claim 1, wherein the first biologicallyactive agent is selected from the group consisting of ivermectin,lufenuron, thunder god extract, cupronickel alloy powder with nano-sizedparticles, cuprozinc and brass alloy powder with nano-sized particles,cuprosilver alloy powder with nano-sized particles, pyrethrin powder,natural pharmacological plant extracts, and natural and synthetic agentshaving a water solubility less than 20 mg/L and having a adsorptioncoefficient above 10,000, and wherein the second biologically activeagent is selected from the group consisting of capsaicin, cupronickelalloy powder with nano-sized particles, pyrethrin, a mixture of metalsalts of pyrithione with nano-sized particles, and cupro-zinc alloy andbrass powder with nano-sized particles.
 11. A method of protecting asurface from biofouling, comprising: applying a first biologicallyactive inner polymer layer on a surface, the first biologically activeinner polymer layer comprising at least one first biologically activeagent that kills a juvenile stage of a biofouling animal organism oncontact with the first biologically active polymer layer; placing aperforated, rigid sheet of fiberglass on a surface of the firstbiologically active inner polymer layer; and applying a secondbiologically active outer polymer layer on the first biologically activeinner polymer layer and the perforated, rigid sheet of fiberglass, thesecond biologically active outer polymer layer comprising at least onesecond biologically active agent, that prevents a larval stage of thebiofouling animal organism from attaching to the second biologicallyactive outer polymer layer, wherein applying the second biologicallyactive outer polymer layer causes material of the second biologicallyactive outer polymer layer to flow through perforations in theperforated, rigid sheet of fiberglass and up against the firstbiologically active inner polymer layer, such that an inner surface ofthe perforated, rigid sheet of fiberglass is immersed in the firstbiologically active inner polymer layer and an outer surface of theperforated, rigid sheet of fiberglass is immersed in the secondbiologically active outer polymer layer.
 12. The method of claim 11,further comprising applying a first primer layer on the surface beforeapplying the first biologically active inner polymer layer.
 13. Themethod of claim 12, wherein the first primer layer comprises an agentthat kills the juvenile stage of the biofouling animal organism.
 14. Themethod of claim 11, further comprising applying a second primer layerafter applying the first biologically active inner polymer layer andbefore applying the second biologically active outer polymer layer. 15.The method of claim 14, wherein the second primer layer comprises anagent selected from the group consisting of an agent that kills thejuvenile stage of the biofouling animal organism and an agent thatinhibits and repels the larval stage of the biofouling animal organism.16. The method of claim 11, wherein the first biologically active innerpolymer layer further comprises a third agent that repels and inhibitsthe larval stage of the biofouling animal organism, with a ratio of theconcentration of the first biologically active agent to the third agentin the biologically active inner polymer layer being 10:1 and whereinthe second biologically active outer polymer layer further comprises afourth agent that kills the juvenile stage of the biofouling organism,with a ratio of the concentration of the second biologically activeagent to the fourth agent in the second biologically active outerpolymer layer being 10:1.
 17. The method of claim 11, wherein the secondbiologically active outer polymer layer is applied before the firstbiologically active inner polymer layer is fully cured to form acontinuous layer characterized by regions of different concentrations ofthe first biologically active agent and the second biologically activeagent, and wherein the rigid sheet of fiberglass is impressed onto thefirst biologically active inner polymer layer and the secondbiologically active outer polymer layer is coated onto both the rigidsheet of fiberglass and the first biologically active inner polymerlayer.
 18. The method of claim 11, wherein the first biologically activeagent comprises a material selected from the group consisting ofivermectin, lufenuron, thunder god extract, cupronickel alloy powderwith nano-sized particles, cuprozinc powder with nano-sized particles,brass alloy powder with nano-sized particles, cuprosilver alloy powderwith nano-sized powder, pyrethrin powder, natural pharmacological plantextracts, and natural and synthetic agents having a water solubilityless than 20 mg/L and having a adsorption coefficient above 10,000 at aconcentration of at least 1% by weight, wherein the second biologicallyactive agent is selected from the group consisting of capsaicin,cupronickel alloy powder with nano-sized particles, pyrethrin, a mixtureof metal salts of pyrithione with nano-sized particles, and cupro-zincalloy and brass powder with nano-sized particles at a concentration ofat least 1% by weight, and wherein the second biologically active outerpolymer layer comprises a mixture of metal salts of pyrithione withnano-sized particles, at a concentration of at least 5% by weight, toinhibit and repel the larval stage of the biofouling animal organism,wherein the mixture of metal salts includes metals selected from thegroup consisting of zinc, silver, barium, strontium, titanium, copper,calcium, and magnesium.